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Highlights: [•] α-Pinene, β-pinene and crude turpentine give similar product distribution in isomerization/dimerization. [•] Dimerization involves a quick isomerization and the dimers are formed from isomeric compounds. [•] Crude turpentine can be used to produce chemicals that are generally formed from pure pinenes, suggesting an efficient and cheap way for turpentine utilization. [•] HPW/MCM-41 is more active than bulk HPW and HPW/Al-MCM-41. [Copyright &y& Elsevier]

Highlights: [•] W18O49/TiO2 hybrid achieves significant synergetic promotion on the photoactivity and photostability. [•] W18O49(10wt%)/TiO2 and W18O49(90wt%)/TiO2 show 2.43 (2.64) and 1.31 (1.52) times higher activity than the calculated baseline in degradation of MO (phenol), under UV–vis and visible light, respectively. [•] Well-matched band structure between W18O49 and TiO2 enhances the photo-induced charge separation and transfer. [•] ·O2 − and hole, especially the former, are the active species involved in the photodegradation. [ABSTRACT FROM AUTHOR]

Abstract: Dye sensitization and nonmetal doping on TiO2 are important for visible-light utilization in many fields. In this work, N, N&S and N&F doped hierarchical macro-/mesoporous TiO2 was prepared using hydrothermal method. Most of the nonmetals exist as surface impurities before calcination, without any visible-light response. Thermal calcination makes N effectively implanted into TiO2 lattice and causes red shift in optical absorption, but S and F are mainly on the surface. The activity of prepared samples for the photodegradation of rhodamine B under visible light was evaluated. The reaction over doped samples without calcination proceeds solely via self-sensitization, and calcination effectively enhances the photodegradation due to nonmetal doping. After being stored for ca. half a year, the activity of all samples are promoted significantly due to the water-mediated adsorption switch from covalent to electrostatic adsorption, caused by pre-bonding of water to surface bridging hydroxyls. The activity of doped samples is further enhanced with water treatment, attributed to the formation of more water-mediated electrostatic modes. The combination of nonmetal doping and water-mediated adsorption switch greatly enhances the visible-light activity of TiO2 (e.g., water-treated N&F-codoped sample shows 6.8-fold higher activity than pure TiO2). [Copyright &y& Elsevier]

Hierarchical TiO2 was prepared via hydrolysis method and characterized by XRD, N2 adsorption–desorption, UV–vis diffusion, and NH3–TPD. With the increase of calcination temperature, the surface area and surface hydroxyls of prepared materials decrease rapidly. The photoactivity was evaluated using the self-sensitized photodegradation of rhodamine B under visible light. The fresh samples show higher activity than P-25 due to higher surface area and more effective light utilization. After stored in air for ca. half a year, the materials show significantly increased photoactivity, due to the prebonding of water on surface bridging hydroxyls, which induces water-mediated adsorption switch from covalent mode to electrostatic one. Water treatment further promotes the photoactivity of stored samples, because more water are bonded on TiO2 surface. It is found that the water-mediated effect closely depends on the surface area and amount of surface bridging hydroxyls. [ABSTRACT FROM AUTHOR]

A series of Al-incorporated mobile crystalline materials (Al-MCM-41) were prepared by hydrothermal synthesis and characterized by XRD, N2 adsorption (isotherms), inductively coupled plasma (ICP) analysis, 27Al magic angle spinning (MAS) NMR spectroscopy, and in situ pyridine adsorption (IR analysis). All samples exhibit an ordered structure with the majority of Al species in framework positions, except those with an SiO2/Al2O3 ratio ≤10. The concentration of acid sites is closely related to the Al content in the unit cell. In the presence of Al-MCM-41, both α- and β-pinenes are quickly transformed into isomerized products, which then couple to form homo- and heterodimers. Lewis acid sites are active in triggering both the isomerization and dimerization reactions, but weak Brønsted acid sites seem inactive for the dimerization. Al-MCM-41 has a greater activity than many other microporous and layered materials, and can be easily regenerated. The activity correlates well with the concentration of acid sites, and the sample with an SiO2/Al2O3 ratio of 20 shows the highest activity. [ABSTRACT FROM AUTHOR]

Abstract: The isomerization of endo-dicyclopentadiene (endo-DCPD) using Al-grafted MCM-41 was studied as an industrial practical synthesis route for exo-DCPD. The catalyst was prepared with post-synthesis grafting method, characterized by XRD, N2 adsorption/desorption, 27Al and 29Si MAS NMR, in-situ pyridine adsorption IR and NH3-TPD. The materials retain ordered mesoporous structure and high surface area. Al atoms are preferentially anchored in tetra-coordination, but these in octa-coordination increase significantly in case of high Al content. The amount of Brønsted acid is closely related to the amount of tetra-coordinated Al species whereas that of Lewis acid corresponding to the total Al content. The prepared material shows higher activity than microporous zeolites because its mesoporous structure gives free diffusion and excellent coke tolerance capability. A good correlation between the conversion of endo-DCPD and the amount of Lewis acid was observed. Specifically, the weak Lewis acid sites catalyze the endo- to exo-isomerization, meanwhile the moderate ones account for the [2+2] cycloaddition of two DCDP molecules. Catalyst with Si/Al of 8 is most active due to its highest concentration of weak Lewis acid. Addition of inert solvent, relatively low reaction temperature and high catalyst dosage can improve the isomerization. The deactivated catalyst can be easily regenerated by calcination. [Copyright &y& Elsevier]

Abstract: The isomerization of endo-tetrahydrodicyclopentadiene (endo-THDCPD) to exo-THDCPD (Jet Propellant-10) and adamantane was investigated using ionic liquid (IL) as acid catalyst to explore an alternative greener than widely applied AlCl3-based operation. ILs composed of various 1-alkyl-3-methylimidazolium chlorides ([RMIM]Cl) and metal chlorides were checked, and [BMIM]Cl/AlCl3 was the best. The effects of acidity and dosage of IL, reaction temperature and time were studied for endo- to exo-isomerization of THDCPD. The reaction occurs quickly under mild conditions with both conversion and selectivity beyond 98%. Purifying the reactant can suppress deactivation of IL; and the used IL can be recycled four times by heating under vacuum after each run. By adjusting the reaction to severe conditions, i.e. higher IL dosage, higher temperature and longer time, exo-THDCPD is further isomerized to adamantane. But both the conversion and selectivity are much lower than those of endo- to exo- isomerization. The highest yield of adamantane is 50.9%, which can be further improved by some additives like 1-bromoadamantane. Compared with other methods, IL catalysis has many advantages from energy and environmental perspectives. [Copyright &y& Elsevier]

Abstract: Tricyclopentadiene (TCPD), product of dicyclopentadiene (DCPD)/cyclopentadiene (CPD) cycloaddition, is a promising candidate as high-energy–density fuel. Thermal [4+2] cycloaddition of DCPD and CPD was simulated using M05-2X/6-311G(d,p) to predict the product distribution. There are four concerted but slightly asynchronous pathways leading to four adducts for endo-DCPD/CPD and exo-DCPD/CPD additions, respectively. The pathways connecting endo-adduct are kinetically preferred compared with those connecting exo-adduct. NB-adducts show higher stability than corresponding CP-adducts. Moreover, exo-isomers are more stable for CP-adducts, but the tendency is inverse for NB-adducts. The predicted product preference is NB-endo>CP-endo>CP-exo>NB-exo. Experiment shows product composition of NB-endo:CP-endo=7.32:1 and NB-endo:CP-endo:CP-exo=3.79:1:0.1 for thermal endo-DCPD/CPD and exo-DCPD/CPD additions, respectively, consistent with the predicted result. However, catalytic reaction gives completely different distribution, in which [4+2] NB-exo and CP-exo, along with at least 21.6% [2+2] adducts, are formed. [Copyright &y& Elsevier]

Abstract: The photoisomerization of norbornadiene using M–Ti–MCM-41 (M=V, Fe and Cr) has been studied to develop an alternative for solar energy accumulation and high energy aerospace fuel synthesis. The photocatalysts were prepared via hydrothermal method and characterized by EDX, XRD, N2 adsorption–desorption, TEM, UV–vis, XPS and IR. With the same Si/M ratio in starting materials, the final concentration of V in the photocatalyst is significantly lower than that of Fe and Cr. V5+ and Fe3+ ions are highly dispersed in Si–O framework with tetrahedral coordination when the metal content is low, and the ordered structure is well retained. However, some species in higher coordination and polymerized environments present with increasing metal content, and the ordered structure becomes to collapse. Cr ions are difficult to get into the framework with various species like extraframework Cr6+ and bulk Cr2O3 formed, also the ordered structure is greatly destroyed. Under UV irradiation, the transition metal ions can improve the photoisomerization activity, with the order of V>Fe>Cr. The activities of V– and Fe–Ti–MCM-41 rise with the increase of Si/M ratio, whereas the performance of Cr–Ti–MCM-41 is irregular. The photocatalysts do not exhibit any activity under visible light, regardless of their absorption in visible-light region. The activity is closely related to the extent of dispersion and local structure of metal ions, about which an indirect excitation process of Ti–O species is suggested. [Copyright &y& Elsevier]

Abstract: The endo- to exo-isomerization of dicyclopentadiene was performed in liquid phase using acidic zeolites. Among the zeolites tested, the activity order is Hβ>HY>HUSY>HZSM-5≈H-mordenite. Beta and Y-type zeolites exhibit higher activity because of their large three-dimensional channels. Surface passivation of Hβ confirms that the reaction proceeds in the inner channels. TG measurements verify that HY is deactivated very quickly because the strong acidity induces serious coke formation, but this phenomenon is much less over beta zeolites. Evaluation on Hβ with different SiO2/Al2O3 ratios indicates that both the weak Lewis acid concentration and isomerization activity of zeolites monotonically decrease with the SiO2/Al2O3 ratio. Thus a weak acid, especially a weak Lewis acid, of Hβ is responsible for the isomerization reaction. Calcination at 500°C provides the highest activity due to complete removal of template residues, generation of large amounts of weak Lewis acid, and good crystal structure. The Hβ concentration was also studied: the optimal value is 15wt%. Zeolites deactivated due to coke deposition can be regenerated by calcination in air flow at 500°C, and there was no obvious activity loss after four times’ regeneration. [Copyright &y& Elsevier]

Abstract: Hydrogenation of dicyclopentadiene (DCPD) to tetrahydrodicyclopentadiene (THDCPD) over nickel alloy catalyst SRNA-4 has been studied. GC–MS analysis showed that the reaction is a consecutive process with two hydrogenated intermediates. DFT simulation confirmed the double bond in norbornene ring is easier to saturate than that in cyclopentene ring, so the major intermediate is 8,9-dihydrodicyclopentadiene (8,9-DHDCPD). In comparison with Raney Ni, SRNA-4 shows a significantly higher activity and makes the reaction proceed at lower temperature. The reaction conditions including temperature and hydrogen pressure were optimized. The optimal hydrogen pressure is 1.5MPa. To avoid the decomposition of DCPD, a two-stage operation was designed: 373K for 1h and then 403K for another 4h. Under these conditions, the yield of THDCPD reaches 98.5%. The apparent kinetics was also calculated using the concentration–time data obtained in the experiments. The activation energy for DCPD to 8,9-DHDCPD and 8,9-DHDCPD to THDCPD reaction is 22.8kJ/mol and 40.9kJ/mol, respectively. [Copyright &y& Elsevier]

Abstract: Zn-doped and La/Zn co-doped TiO2 nanoparticles were prepared by sol–gel method and utilized as the photocatalysts for the isomerization of norbornadiene to quadricyclane that has significant potential for solar energy storage and high-energy fuel synthesis. For Zn-doped samples, Zn ions do not enter the TiO2 lattice, but distribute on the particle surface in the form of ZnO crystallites. These crystallites inhibit the agglomeration, growth and anatase-to-rutile phase transformation of TiO2. The prepared particles contain considerable amount of surface-bound OHs, especially for 1%Zn/TiO2. A red shift in the optical absorption is observed due to the electron transfer between TiO2 and ZnO. In the photocatalytic isomerization reaction, Zn-doped TiO2 exhibits higher activity than homogenous sensitizer like Ethyl Michler''s Keton, and 1%Zn/TiO2 produces the highest yield of quadricyclane. To further enhance the activity, 1%Zn/TiO2 was co-doped with La. La2O3 crystallites also distribute on the surface of TiO2, similar to the case of ZnO. The particle size is reduced to <7nm but the surface-bound OHs are decreased to some degree. There is a significant blue shift in the optical absorption with a sharply increased absorbance in the UV region due to the quantum-size effect. 5%La–1%Zn/TiO2 and 3%La–1%Zn/TiO2 exhibit higher activity compared with 1%Zn/TiO2, but higher or lower content of La is detrimental to the reaction. It is concluded that doping Zn can significantly increase the surface-bound OHs, whereas doping La reduces the particle to quantum-size at the expense of surface-bound OHs. A good compromise between the two factors eventually provides a high activity. The isomerization reaction over semiconductors is proposed to proceed through an exciplex (charge-transfer) intermediate. [Copyright &y& Elsevier]

Abstract: A glow discharge plasma treatment was used to modify the impregnation method to prepare photocatalysts with the following steps: impregnation, cold plasma treatment, calcination, and reduction. The activity and properties of the catalysts were studied in comparison with those prepared with traditional impregnation method. The activities for hydrogen generation from water/alcohols mixtures were significantly promoted. The properties including the metal dispersion, near-UV absorption, and metal stability were also enhanced. The enhanced metal dispersion and optical absorption partly promoted the activity but the effect was limited. It was speculated that the plasma method produced an enhanced metal–support interaction. According to high-resolution TEM observation, a greatly distorted metal–support interface was formed on the plasma prepared catalyst. This interface allowed a close contact between the metal atoms and support lattices, which supported the existence of the enhanced interaction. This interface was expected to facilitate the electron transfer during photocatalytic reaction and be the major reason for the high activity of the plasma prepared photocatalysts. [Copyright &y& Elsevier]

Abstract: Pd-B/γ-Al2O3 amorphous catalysts were prepared through impregnation and KBH4 reduction for the hydrogenation of tricyclopentadiene. The effects of reduction conditions, pre-calcination and thermal annealing on the hydrogenation activity were studied. It is found that the reduction should be conducted in ice water batch with KBH4 solution added by dropping to avoid the crystallization of amorphous metals. Pre-calcination of the catalyst before reduction can increase the amount of Pd on the prepared catalyst. With pre-calcination at 200°C, the highest hydrogenation turnover frequency is obtained. The amorphous catalyst is thermally stable at temperature below 150°C. When annealed at higher temperature, the amorphous metals are gradually crystallized and the particle size is increased. After annealing at 600°C, the catalyst is uniformly crystallized. It is noticed that the size of amorphous Pd calculated from H2-adsorption is much smaller than the actual size observed by transmission electron microscope (TEM). This indicates that amorphous metal has stronger H2-adsorption ability than crystal metals with comparative particle sizes. The hydrogenation activity decreases with the increase of annealing temperature. Moreover, the hydrogenation activity is solely dependent on the amount of H2-adsorption, suggesting that the excellent performance of amorphous catalyst should be attributed to their better H2-adsorption ability. [Copyright &y& Elsevier]

Dimethyl ether (DME), with its non-toxic character, high H/C ratio and high-energy volumetric density, is an ideal resource for hydrogen production. This work presents a hydrogen production from partial oxidation of DME using corona discharge plasma performed at ambient conditions. The partial oxidation can avoid the undesired carbon deposit existing in the decomposition of DME and a stable operation has been obtained. The carbon deposit is completely avoided when the O2/DME ratio is 1.05. Partial oxidation can also greatly improve the conversion rate and energy efficiency. The optimal O2/DME ratio is 1.38, with which the rate of H2 production is 1.33 times higher and the energy efficiency is 1.72 times higher than that of DME decomposition. The higher O2/DME ratio results in complete oxidation and reduces the rate of H2 production. AC plasma is more efficient than the DC plasma and the optimum frequency is 2kHz. The order of desired waveform is: sinusoid sinusoid triangular square ramp. [Copyright &y& Elsevier]

Abstract: Dimethyl ether (DME), with its non-toxic character, high H/C ratio and high-energy volumetric density, is an ideal resource for hydrogen production. In this work, hydrogen production from the decomposition of DME using corona discharge has been studied. The corona discharge plasma decomposition was conducted at ambient conditions. The effects of dilution gas (argon), flow rate, frequency and waveforms on the DME decomposition were investigated. The addition of dilution gas can significantly increase the hydrogen production rate. The highest hydrogen production rate with the lowest energy consumption presents at the flow rate of 27.5Nmlmin−1. AC voltage is more favored than DC voltage for the production of hydrogen with less energy input. The optimal frequency is 2.0kHz. The hydrogen production rate is also affected by the input waveform and decreases as following: sinusoid triangular>sinusoid>ramp>square, whereas the sinusoid waveform shows the highest energy efficiency. The corona discharge decomposition of DME is leading to a simple, easy and convenient hydrogen production with no needs of catalyst and external heating. [Copyright &y& Elsevier]

Abstract: Large-scale synthesis of NiO-embedded carbon nanotubes (CNTs) has been achieved using a nanoporous anodic aluminum (AAO) membrane as a template, with the aid of CH4/H2 corona discharge enhanced chemical vapor deposition (CVD). NiO nanoparticles are first introduced into the nanopores of the alumina template through wet impregnation method. The loading of NiO nanoparticles into the CNTs and the synthesis of the CNTs were simultaneously performed in the corona discharge reactor. Transmission electron microscopy characterization showed that the NiO nanoparticles are encapsulated into the walls of the CNTs, but not present on the outer surfaces. [Copyright &y& Elsevier]

Abstract: Pt nanoparticles were supported on the TiO2 surface using a glow discharge modified impregnation method. The metal–semiconductor interface structure was observed by high-resolution TEM. The fringes of Pt[111] were nearly perpendicular to those of TiO2[101] at the interface. Such alignment relationship resulted in a largely distorted interface allowing a close contact and enhanced interaction between the metal and the semiconductor. When used as photocatalyst, this Pt–TiO2 interface could improve the photo-induced electron transfer from the semiconductor to the metal and promote the near-UV absorption. The photocatalyst with such interface exhibited higher activity for hydrogen generation from alcohol/water mixture than that with a less distorted interface. [Copyright &y& Elsevier]

Abstract: Highly efficient Pt/TiO2 photocatalyst has been prepared using plasma-enhanced impregnation method. Impregnated 0.5 wt%Pt/TiO2 was treated by plasma followed with thermal calcinations and hydrogen reduction. The catalyst characterizations show that Pt is highly dispersed with a size of 3–5 nm. UV–Vis reflection spectrum suggests it a high photosensitivity in near UV region. Such plasma prepared catalyst exhibits a much higher activity and better metal stability for hydrogen generation from methanol/water mixture, compared to the catalyst prepared conventionally. This highly efficient photocatalyst should have extensive applications in photocatalytic processes. [Copyright &y& Elsevier]

A novel method for starch modification is investigated. Starch is highly cross linked by glow discharge plasma, without the assistance of conventional chemical agents, thus avoiding any environmental concerns. An energy-charge-transfer mechanism is suggested for the function of plasma. This process could be useful for the production of large quantities of modified starch. [Copyright &y& Elsevier]

Herein, a Mott-Schottky heterojunction catalyst was developed by incorporating nickel (Ni) nanometallic particles supported on nitrogen-doped carbon-coated TiO 2 , enabling full-spectrum light absorption and facilitating a robust metal-support interface. This catalyst demonstrated exceptional performance in photo-thermal catalysis. Specifically, the Ni/0.5-TiO 2 @NC catalyst achieved a CO 2 hydrogenation rate of 65.3 mmol/(g cat ·h) with a CH 4 selectivity exceeding 99% under full-spectrum illumination. Remarkably, the catalyst exhibited excellent stability, maintaining its performance over two reaction cycles. The strong metal-support interface of the Mott-Schottky heterojunction catalyst enhanced photo-generated electron-hole separation efficiencies, leading to a substantial rise in catalyst surface temperature. Consequently, this phenomenon accelerated the reaction kinetics and lowered the activation energy, thereby improving overall efficiency. [Display omitted] • Mott-Schottky heterojunctions consisting of TiO 2 @NC-support and highly dispersed Ni NPs catalysts were successfully prepared. • The Mott-Schottky heterojunction catalysts exhibit rapid interface electron transfer, leading to superb carrier separation efficiencies. • The Ni/0.5-TiO 2 @NC catalyst demonstrates exceptional photo-thermal co-catalytic effects, resulting in outstanding performance in the RWGS reaction. • The in-situ DRIFTS analysis revealed that the mechanism governing the photo-thermal co-catalytic RWGS reaction follows the *HCOO pathway. Photo-thermal co-catalytic reduction of CO 2 to synthesize value-added chemicals presents a promising approach to addressing environmental issues. Nevertheless, traditional catalysts exhibit low light utilization efficiency, leading to the generation of a reduced number of electron-hole pairs and rapid recombination, thereby limiting catalytic performance enhancement. Herein, a Mott-Schottky heterojunction catalyst was developed by incorporating nitrogen-doped carbon coated TiO 2 supported nickel (Ni) nanometallic particles (Ni/x-TiO 2 @NC). The optimal Ni/0.5-TiO 2 @NC sample displayed a conversion rate of 71.6 % and a methane (CH 4) production rate of 65.3 mmol/(g cat ·h) during photo-thermal co-catalytic CO 2 methanation under full-spectrum illumination, with a CH 4 selectivity exceeding 99.6 %. The catalyst demonstrates good stability as it shows no decay after two reaction cycles. The Mott-Schottky heterojunction catalysts display excellent efficiency in separating photo-generated electron-hole pairs and elevate the catalysts' temperature, thus accelerating the reaction rate. The in-situ experiments revealed that light-induced electron transfer effectively facilitates H 2 dissociation and enhances surface defects, thereby promoting CO 2 adsorption. This study introduces a novel approach for developing photo-thermal catalysts for CO 2 reduction, aiming to enhance solar energy utilization and facilitate interface electron transfer. [ABSTRACT FROM AUTHOR]

Quantum dot (TiO2) self-decorated and defect-free anatase nanosheets were fabricated by a long-time hydrothermal strategy and subsequent defect healing. Such decoration provides a new and effective charge transfer pathway over the nanosheet surface, leading to remarkably high photoactivity. [ABSTRACT FROM AUTHOR]

Lignin is the main component of lignocellulose and the largest source of aromatic substances on the earth. Biofuel and bio‐chemicals derived from lignin can reduce the use of petroleum products. Current advances in lignin catalysis conversion have facilitated many of progress, but understanding the principles of catalyst design is critical to moving the field forward. In this review, the factors affecting the catalysts (including the type of active metal, metal particle size, acidity, pore size, the nature of the oxide supports, and the synergistic effect of the metals) are systematically reviewed based on the three most commonly used supports (carbon, oxides, and zeolites) in lignin hydrogenolysis. The catalytic performance (selectivity and yield of products) is evaluated, and the emerging catalytic mechanisms are introduced to better understand the catalyst design guidelines. Finally, based on the progress of existing studies, future directions for catalyst design in the field of lignin depolymerization are proposed. [ABSTRACT FROM AUTHOR]

Liquid organic hydrogen carrier technology is a promising alternative for hydrogen storage and transportation. Benzyltoluene (BT) is a high-performance hydrogen storage carrier, but the hydrogenation kinetic parameters that are important to guide reactor and catalyst design are not clear. Here, we systematically investigated the kinetics of BT hydrogenation over a supported Ni catalyst for its potential application in hydrogen storage. Our results suggest that BT hydrogenation reaction follows a two-step series reaction from BT to 12H-BT with 6H-BT as the intermediate. The reaction order is 0 and 1 with respect to BT and 6H-BT concentration, respectively, whereas that with respect to H 2 pressure is approximately equal (1.0 and 1.1 for BT and 6H-BT hydrogenation, respectively). Calculated activation energy suggests that 6H-BT hydrogenation is the rate-determining step in the whole process. Moreover, both kinetic and DFT results indicate that the presence of BT would inhibit the further 6H-BT hydrogenation to 12H-BT. This study is expected to provide a new understanding of BT hydrogenation reactions and a useful guideline for reactor and catalyst design. • This work investigated BT hydrogenation kinetics over Ni catalysts for its application in hydrogen storage. • BT hydrogenation follows a two-step reaction via 6H-BT intermediates, and 6H-BT hydrogenation is the rate-limiting step. • Experimental and theoretical results indicate BT has an inhibitory effect on the 6H-BT hydrogenation. [ABSTRACT FROM AUTHOR]

Incorporating g-C 3 N 4 with transition metal phosphides is emerging as a low-cost and robust co-catalyst for hydrogen evolution. The ammonia borane hydrolysis is an efficient method to release H 2 at ambient conditions in the presence of a catalyst. An efficient and cheap catalyst is needed for practical application to achieve this benchmark. For this purpose, a catalyst Ni 2 P/C 3 N 4 is synthesized by hydrothermal method and low-temperature phosphidation. The optimization reveals that the Ni 2 P/C 3 N 4 with 6.5% Ni contents shows the best performance for H 2 release. Furthermore, 2% Pt nanoparticles loading over Ni 2 P/C 3 N 4 boosts the charge transfer and improves activity 5.7-fold compared to Ni 2 P/C 3 N 4 , and the Pt-loaded catalyst is depicted as Pt@Ni 2 P/C 3 N 4. The reaction kinetics reveals that the hydrogen evolution rate accelerates by increasing the amount of Pt@Ni 2 P/C 3 N 4 and AB concentration, and the loading of Pt nanoparticles loaded over Ni 2 P/C 3 N 4 reduces the activation energy significantly. Moreover, the ionic interaction between Pt and Ni 2 P/C 3 N 4 generates Ptᵟ+ and (Ni 2 P/C 3 N 4)ᵟ− active sites which facilitates B–H cleavage and O–H bonds of ammonia borane and water, respectively. Incorporating transition metals phosphide and noble metals supported over g-C 3 N 4 paves the pathway toward the efficient H 2 evolution from ammonia borane, bringing cost-effective modifications to synthesize constructive catalysts. Hydrogen evolution in the presence of Pt@Ni 2 P/CN. [Display omitted] • The best activity is achieved with 6.5% nickel content for synthesized Ni 2 P/C 3 N 4. • The 2% Pt NPs loaded over Ni 2 P/C 3 N 4 reduces the activation energy. • Ptᵟ+ and (Ni 2 P/C 3 N 4)ᵟ− serve as active sites to enhance the catalytic activity. [ABSTRACT FROM AUTHOR]

Schematic diagram: Synergetic effect of Au NPs loading over Ni 2 P & CoP for H 2 evolution. [Display omitted] • The catalysts (Au/Ni 2 P, Au/CoP) are synthesized and optimized. • The XPS reveals that the synergetic effect of Au/Ni 2 P is stronger than Au/CoP. • The activation energy of Au/CoP is less than Au/Ni 2 P. • Active sites for ammonia-borane hydrolysis are Auδ+ and (Ni 2 P & CoP) δ-. The hydrogen evolution from ammonia borane is intriguing but challenging due to its sluggish kinetics. In this regard, the gold nanoparticles amalgamation with metal phosphides is speculated to be more efficient catalysts. Here, the catalysts Au/Ni 2 P and Au/CoP with the high synergetic effect of Au nanoparticles and metal phosphides were synthesized for ammonia borane hydrolysis. The activity of Au/Ni 2 P increases 4.8-fold (i.e., 0.08 to 0.40 L∙h−1) compared to pristine Ni 2 P, and the activity of Au/CoP increases 1.7-fold (i.e., 0.74 to 1.27 L∙h−1) compared to pristine CoP. This reveals that the synergetic effect of Auδ+ and (Ni 2 P) δ- is stronger than Auδ+ and (CoP) δ- which is manifested by XPS analysis. The kinetics exposes that the activation energy of Au/Ni 2 P (45.28 kJ∙mole-1) is greater than Au/CoP (31.45 kJ∙mole-1) and the TOF of Au/Ni 2 P is less than Au/CoP. This research work presents an effective approach for producing active sites of Auδ+ and (Ni 2 P & CoP) δ- for ammonia borane hydrolysis to enhance the H 2 evolution rate. [ABSTRACT FROM AUTHOR]

The effects of different masks and patterns on the top stripping of GaAs microwire arrays fabricated by inductively coupled plasma etching for 20 min and 40 min are investigated. The results show that the mask layer is the main affect of the top stripping of the GaAs microwires in 40 min. Increasing the mask layers and reducing the photoresist layers can prevent top stripping and result in a suitable GaAs microwire array. [ABSTRACT FROM AUTHOR]

The conversion of biomass is a favorable alternative to the fossil energy route to solve the energy crisis and environmental pollution. As one of the most versatile platform compounds, 5‐hydroxymethylfural (HMF) can be transformed to various value‐added chemicals via electrolysis combining with renewable energy. Here, the recent advances in electrochemical oxidation of HMF, from reaction mechanism to reactor design are reviewed. First, the reaction mechanism and pathway are summarized systematically. Second, the parameters easy to be ignored are emphasized and discussed. Then, the electrocatalysts are reviewed comprehensively for different products and the reactors are introduced. Finally, future efforts on exploring reaction mechanism, electrocatalysts, and reactor are prospected. This review provides a deeper understanding of mechanism for electrochemical oxidation of HMF, the design of electrocatalyst and reactor, which is expected to promote the economical and efficient electrochemical conversion of biomass for industrial applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A two-step cystine-mediated strategy is developed to alter the symmetry structure of C 3 N 4. • CN-25CYS possesses alkyl groups and nitrogen vacancies. • The distorted arrangements activate n-π* electron transition of carbon nitride. • The spatial separation of oxidation and reduction sites promotes charge separation. • CN-25CYS achieves 9.6-fold and 15.6-fold higher H 2 production rates and RhB degradation rates. The periodical distribution of N and C atoms in the carbon nitride skeleton results in intrinsically insufficient light absorption and serious carrier recombination. Herein, an efficient two-step cystine-mediated strategy was developed to alter the structure symmetry of C 3 N 4 via the introduction of alkyl groups and nitrogen vacancies. The experimental analysis and theoretical calculation confirm that the formation of alkyl groups and nitrogen vacancies can modulate band structure and activate n-π* electron transition. Especially, the charge density in CN-25CYS is redistributed with spatial separation of oxidation and reduction sites, suppressing photogenerated charge recombination effectively. Therefore, the distorted carbon nitride (CN-25CYS) exhibits 9.6-times and 15.6-times higher photoreaction rates in hydrogen production and RhB degradation than the pristine one (CN-0CYS), respectively. [ABSTRACT FROM AUTHOR]

Photocatalysis can create a green way to produce clean energy resources, degrade pollutants and achieve carbon neutrality, making the construction of efficient photocatalysts significant in solving environmental issues. Conjugated polymers (CPs) with adjustable band structures have superior light‐absorption capacity and flexible morphology that facilitate contact with other components to form advanced heterojunctions. Interface engineering can strengthen the interfacial contact between the components and further enlarge the interfacial contact area, enhance light absorption, accelerate charge transfer and improve the reusability of the composites. In order to throw some new light on heterojunction interface regulation at a molecular level, herein we summarize CP‐based composites with improved photocatalytic performance according to the types of interactions (covalent bonding, hydrogen bonding, electrostatic interactions, π‐π stacking, and other polar interactions) between the components and introduce the corresponding interface building methods, identifying techniques. Then the roles of interfaces in different photocatalytic applications are discussed. Finally, we sum up the existing problems in interface engineering of CP‐based composites and look forward to the possible solutions. [ABSTRACT FROM AUTHOR]

The piezo‐Fenton system has attracted attention not only because it can enhance the Fenton reaction activity by mechanical energy input, but also because it is expected to realize a class of stimuli‐responsive advanced oxidation systems by regulating energy input and hydrogen peroxide self‐supply, thus greatly enriching the application possibilities of Fenton chemistry. In this work, a series of Fe‐doped g‐C3N4 (g‐C3N4‐Fe) as a piezo‐Fenton system were synthesized where the iron stably immobilized through Fe−N interaction. The piezo‐induced electrons generate on g‐C3N4 matrix support the conversion of Fe(III) to Fe(II) and promote rate‐limiting step of Fenton reaction. With the optimal Fe loading, g‐C3N4‐0.5Fe can achieve methylene blue (MB) degradation under ultrasonic treatment with first‐order kinetic rate constants of 75×10−3 min−1. Most importantly, the g‐C3N4‐Fe can maintain good catalytic activity in a wide pH range (pH=2.0∼9.0) and be cyclic used without iron leaching to solution (<0.001 μg ⋅ L−1), overcoming the disadvantage of traditional Fe‐based Fenton catalysts that can only be applied under acidic conditions and prone to secondary pollution. In addition, g‐C3N4‐0.5Fe also exhibits antibacterial properties of Escherichia coli and Staphylococcus aureus under ultrasound. Hydroxyl radicals mainly contribute to the degradation of MB and the sterilization process. Our work is an attempt to clarify the role of g‐C3N4‐Fe in the conversion of mechanical energy to ROS and provide inspirations for the piezo‐Fenton system design. [ABSTRACT FROM AUTHOR]

[Display omitted] • The dynamics and mechanism of JP-10 thermal oxidative deposition were investigated. • Both the peak deposit thickness and deposits volume of JP-10 increase with temperature. • The apparent deposition activation energy of JP-10 is approximately 71.2 kJ/mol. • The thermal oxidative deposition of JP-10 occurs via a series of radical reactions. High-energy–density (HED) fuels (like JP-10) have drawn more and more attention for volume-limited aerospace vehicles to extend the flight range and/or increase the payload. However, their thermal oxidation and deposition performance are still ambiguous. In this work, the dynamics and mechanism of JP-10 thermal oxidative deposition were investigated by the jet fuel thermal oxidation stability tester (JFTOT), ellipsometric tube rater (ETR) and comprehensive two-dimensional gas chromatography coupled with mass spectrometry and flame ionization detector (GC × GC–MS/FID). The results reveal that both the peak deposit thickness and total deposits volume of JP-10 increase with increasing temperature with the apparent deposition activation energy of approximately 71.2 kJ/mol. The deposits on the tube surface have globular structure, and they undergo particle formation, growth, adherence, agglomeration and size reduction during thermal stress. The fine characterizations of liquid products after JFTOT test confirm that the thermal oxidative deposition of JP-10 occurs via a series of radical reactions, such as oxidative decomposition and radical addition, which will be significantly accelerated at higher temperature. Importantly, the stability of alkoxy radical seems to be a significant factor affecting the thermal oxidation stability of HED fuels. This work may shed light on the possible deposition mechanism of HED fuels and will guide the rational design of HED fuels with high thermal oxidation stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Defective TEB-DBT CMPs with alkynyl defects via the molecular design are constructed. • Combination of the DFT calculations and experimental results, the incorporation of alkynyl defect accelerates the separation of photogenerated charge carriers. • The microstructure, band structure, and photocatalytic performance of CMPs can be regulated by varying the content of alkynyl defect. Defect engineering is a versatile approach to modulate band and electronic structures as well as materials performance. Nowadays, more research has been performed for enhancing catalytic performance of organic photocatalysts via the regulation of structure defect. Herein, we constructed the dibenzo[b,d]thiophene-sulfone-based conjugated microporous polymers (CMPs) with alkynyl defects via the molecular design. The effects of the concentration of alkynyl defects on the optical band gap, energy level structure, charge separation and photoactivity of the as-prepared samples were further explored. Combination of the first-principle density functional theory (DFT) calculations and experimental results, the incorporation of alkynyl defects accelerated the separation of photogenerated charge carriers. Furthermore, the concentration of alkynyl defects in CMPs can be adjusted by the dosage of 1,3-diethynylbenzene (MEB), thereby modulating the electronic structure and charge carrier separation properties. At appropriate alkynyl defect concentration, the prepared Defect-TD-2 shows higher visible-light photocatalytic performance for H 2 production and pollutants degradation. The work therefore shows an efficient self-modification strategy for improving the photoactivity of CMPs. [ABSTRACT FROM AUTHOR]

One pot synthesis of 2,5‐dimethylfuran (2,5‐DMF) from saccharides under mild conditions is of importance for the production of biofuel and fine chemicals. However, the synthesis requires a multitude of active sites and suffers from slow kinetics due to poor diffusion in most composite catalysts. Herein, a metal‐acid functionalized 2D metal‐organic framework (MOF; Pd/NUS‐SO3H), as an ultrathin nanosheet of 3–4 nm with Lewis acid, Brønsted acid, and metal active sites, was prepared based on the diazo method for acid modification and subsequent metal loading. This new composite catalyst gives substantially higher yields of DMF than all reported catalysts for different saccharides (fructose, glucose, cellobiose, sucrose, and inulins). Characterization suggests that a cascade of reactions including polysaccharide hydrolysis, isomerization, dehydration, and hydrodeoxygenation takes place with rapid molecular interactions. [ABSTRACT FROM AUTHOR]

One pot synthesis of 2,5‐dimethylfuran (2,5‐DMF) from saccharides under mild conditions is of importance for the production of biofuel and fine chemicals. However, the synthesis requires a multitude of active sites and suffers from slow kinetics due to poor diffusion in most composite catalysts. Herein, a metal‐acid functionalized 2D metal‐organic framework (MOF; Pd/NUS‐SO3H), as an ultrathin nanosheet of 3–4 nm with Lewis acid, Brønsted acid, and metal active sites, was prepared based on the diazo method for acid modification and subsequent metal loading. This new composite catalyst gives substantially higher yields of DMF than all reported catalysts for different saccharides (fructose, glucose, cellobiose, sucrose, and inulins). Characterization suggests that a cascade of reactions including polysaccharide hydrolysis, isomerization, dehydration, and hydrodeoxygenation takes place with rapid molecular interactions. [ABSTRACT FROM AUTHOR]

• Introduce the mechanism of LHF steam reforming (SR), defines the main problems faced by the current reactions and catalysts. • Systematically summarize recent progress in the development of catalysts for SR of LHFs. • The applications of LHF SR are highlighted, including hydrogen production, fuel cell, and engine thermal management. • The enhancement technologies for LHF SR process are described. • The challenges and perspectives of SR of LHF are discussed and proposed. Liquid hydrocarbon fuels (LHFs) possessing the features of high energy density, large content of hydrogen volume and convenient storage and transportation have received great attention in hydrogen production, fuel cell, and national defense weapon application. However, the efficiency of LHF conversion is still far from satisfying at present, especially suffering from low conversion of the reaction and quick deactivation of the catalyst. The synthesis of robust and low-price catalysts is crucial for LHF conversion. Recently, significant progress has been achieved in regulating the composition, structure, and active site of catalyst and understanding the structure–activity relationship. At first, this review discusses the mechanism of LHF steam reforming (SR), defines the main problems faced by the current reactions and catalysts to guide the design and development of high-performance catalysts. Then, recent progress in the development of catalysts for SR of LHFs is systematically summarized, including gasoline, kerosene, diesel, tar and sulfur containing hydrocarbon fuel. Thereafter, the relevant applications of LHF SR are highlighted, including hydrogen production, fuel cell, and engine thermal management. Finally, several enhancement technologies for SR process are described, including plasma reforming, chemical looping reforming, adsorption enhanced reforming and reaction separation coupling reforming technology. The advantage and disadvantage of various technologies are explained, and the enhanced conversion of LHF is expected to be realized through the construction of high-efficient catalysts coupling of enhancement technology and unique reactor. We hope that this review can provide the relevant guidance and new ideas for the technological development of hydrogen production, fuel cell, and engineering thermal management via SR of LHFs. [ABSTRACT FROM AUTHOR]

• Methyl-substituted decalin was synthesized by one-step alkylation reaction. • The synthesized fuel possesses high density and well cryogenic properties. • The pseudo reaction kinetics of alkylation reactions are investigated in detail. • A mechanism of decalin methylation reaction with solvent and catalyst was proposed. Alkyl decalins are promising jet fuel components with high density and well cryogenic properties, but are difficult to obtain. Here we bring up a facile approach to synthesize methyl-substituted decalins including methyl decalin, dimethyl decalin and trimethyl decalin via catalytic alkylation reaction. The reaction conditions are optimized to obtain the high decalin conversion of 83.1 %. Based on a series of experiments, it is indicated that the intermediate complex formed by tetramethylsilane, aluminum chloride and dichloroethane is the key to accelerate the reaction rate, and the reaction mechanism is proposed. Moreover, a pseudo-first-order irreversible reaction dynamics is studied, and the reaction kinetics parameters and reaction rate equati andons are obtained. After vacuum distillation, the fuel product shows high density (0.872 g/cm3) and high volumetric neat heat of combustion (36.9 MJ/L), much higher than those of RP-3 fuel. This work provides a facile method to synthesize high-performance jet fuel. [ABSTRACT FROM AUTHOR]

Developing a one-pot method for tandem hydrogenolysis–hydrogenation of biomass-derived furan-based alcohols to methyltetrahydrofurans is challenging but crucial for synthesizing sustainable biofuels and chemicals. Herein, we report the efficient hydrogenolysis–hydrogenation of furan alcohol to 2-methyltetrahydrofuran using a phosphate-supported synergistic palladium single atom and nanoparticle at an ambient temperature. Comprehensive characterizations and theoretical calculations reveal that in situ H 2 heterolysis at the palladium single atom–AlPO 4 interface generates frustrated Lewis H+–H− pairs, which selectively cleaves the C–OH bond in furan alcohol to form 2-methylfuran, and H atoms on the palladium nanoparticle surface promotes the subsequent C C hydrogenation of 2-methylfuran to 2-methyltetrahydrofuran. Additionally, the catalyst shows generality for various furan and heterocyclic alcohols. Furthermore, the catalyst exhibits excellent activity in the hydrogenation–hydrogenolysis–hydrogenation of furan aldehydes to methyltetrahydrofurans. The results provide a highly efficient reaction for synthesizing methyltetrahydrofurans at ambient temperature, which has excellent potential for industrial applications. [Display omitted] • Phosphate-supported synergistic palladium single atom and nanoparticle was fabricated. • Methyltetrahydrofurans was selectively obtained from tandem hydrogenolysis–hydrogenation of furan alcohols. • In situ H 2 heterolysis-generated H−–Pd–P–O-H+ site over palladium single atom provides the C–OH hydrogenolysis site. • Palladium nanoparticle promotes the subsequent C C hydrogenation. • The catalyst shows generality for various furan and heterocyclic alcohols. [ABSTRACT FROM AUTHOR]

[Display omitted] • A highly selective hydrodeoxygenation of 5-hydroxymethylfurfural was conducted by intelligent regulation and usage of Ni/MCM-41 and Pt-WO X /t-ZrO 2. • 1-hexanol in 76 % yield is firstly synthesized using 5-hydroxymethylfurfural. • The mechanism of synthesis of 1-hexanol using 5-hydroxymethylfurfural is explored. • 5-hydroxymethylfurfural is a biomass. Metal-metal oxide catalysts are robust in selective hydrodeoxygenation of biomass derives. Herein, 1-hexanol in total yield about 76 % is firstly achieved by high selective hydrodeoxygenation of 5-hydroxymethylfurfural over Ni/MCM-41 and Pt-WO X /t-ZrO 2. By controlling the amount ratio of Ni/Ni2+ to 0.46, a 99.9 % yield of 2,5-tetrahydrofurandimethanol was achieved from 5-hydroxymethylfurfural by Ni/MCM-41. Subsequently high yield of 76 % of 1-hexanol was obtained by competing pathways of tandem reactions beginning at SN2 reaction at the epoxy atom of 2,5-tetrahydrofurandimethanol to enol/tautomer intermediates and ending with controllable selective hydrogenation. The reaction mechanism is explored and the reaction-oriented regulation is realized by the additional strong BrÖnsted acid sites generated by electron transfer from W to Pt and the appropriate amount of Pt0 sites of Pt-WO X /t-ZrO 2 , where the ratios of W5+/W6+ and Pt0/Pt2+ are 0.31 and 4.58 respectively. This work provides a new and green method for the synthesis of 1-hexanol and expands the utilization of metal–metal oxide in making value-added products using sustainable feedstocks. [ABSTRACT FROM AUTHOR]

Directional reconstructed CoP-Cu/Co(OH) 2 promotes the synergistic catalysis of NO 3 −RR to deliver satisfactory ammonia production rate (9.91 mmol h−1cm−2) and high Faraday efficiency (99.2 %) with appreciable economic benefits at industrial-level current densities. [Display omitted] • Self-supported CoP-Cu heterojunction is successfully prepared by a simple method. • The reconstructed CoP-Cu/Co(OH) 2 boosted the NO 3 −RR performance via synergistic catalysis. • CoP-Cu/Co(OH) 2 delivers the NH 3 yield rate of 9.91 mmol h−1cm−2 with the FE of 99.2 % at industrial-level current density. • The assembled MEA system can be operated efficiently and stably under industrial conditions. • Techno-economic analysis exhibits appreciable economic benefits of our system. The electrochemical reduction of nitrate (NO 3 −RR) represents a compelling approach for the treatment of wastewater, serving as both a sustainable substitute to the energy-intensive Haber-Bosch process and a viable alternative to direct electroreduction of N 2. However, the process involves multiple electron and proton transfer steps and a complex reaction pathway, leading to low Faraday efficiency and selectivity. Herein, we demonstrated a directional surface reconstruction to generate CoP-Cu/Co(OH) 2 heterojunction for synergistic catalysis of NO 3 −RR. Impressively, a high ammonia generation rate of 9.91 mmol h−1cm−2 and a Faraday efficiency of 99.2 % can be achieved at an industrial-relevant current density of 2 A cm−2. Moreover, the catalyst exhibited exceptional durability, maintaining the activity for 110 h under industrial current density. Such outstanding NO 3 −RR performance can be ascribed to the synergistic catalytic effect among the active sites of Cu, CoP and Co(OH) 2 , as well as the excellent stability of self-supported catalyst. Specifically, Cu and CoP sites synergistically promote the conversion of NO 3 − to NO 2 − and NO 2 − to NH 3. Meanwhile, the partial reconstructed Co(OH) 2 from CoP enhances water dissociation, thereby supplying active hydrogen (*H) essential for NO 3 −RR. When applied to a membrane electrode assembly (MEA) system, CoP-Cu/Co(OH) 2 can deliver satisfactory ammonia production rate with appreciable economic benefits at industrial-level current densities, highlighting its potential for industrial applications. [ABSTRACT FROM AUTHOR]

Ag 2 O/P25 and Ag/P25 catalysts were synthesized and applied in the photocatalytic reduction of nitrate with formic acid as a hole scavenger. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscope (TEM) analysis demonstrate that Ag 2 O or Ag nanoparticles were well distributed on the surface of P25. Under UV irradiation, 5% Ag 2 O/P25 showed a fast rate (0.95 h −1 , 6.3 times of P25), a high conversion (97.2%, 3.63 times of P25) and a high N 2 selectivity (83.1%, 1.15 times of P25) for nitrate reduction. The improved separation of electron–hole pairs on Ag 2 O/P25 results in the high conversion of nitrate. Moreover, compared with the Ag/P25 catalyst, Ag 2 O/P25 exhibited a good reusability in nitrate reduction. The formed Ag–Ag 2 O structure [Ag(0) present on the surface of Ag 2 O] over P25 by partial photoreduction of deposited Ag 2 O contributed to the better stability of Ag 2 O/P25 in nitrate reduction. The present study provides a new sight into the use of Ag 2 O/P25 catalyst in the reduction of nitrate. [ABSTRACT FROM AUTHOR]

The excessive dependence on fossil fuels contributes to the majority of CO2 emissions, influencing on the climate change. One promising alternative to fossil fuels is green hydrogen, which can be produced through water electrolysis from renewable electricity. However, the variety and complexity of hydrogen evolution electrocatalysts currently studied increases the difficulty in the integration of catalytic theory, catalyst design and preparation, and characterization methods. Herein, this review first highlights design principles for hydrogen evolution reaction (HER) electrocatalysts, presenting the thermodynamics, kinetics, and related electronic and structural descriptors for HER. Second, the reasonable design, preparation, mechanistic understanding, and performance enhancement of electrocatalysts are deeply discussed based on intrinsic and extrinsic effects. Third, recent advancements in the electrocatalytic water splitting technology are further discussed briefly. Finally, the challenges and perspectives of the development of highly efficient hydrogen evolution electrocatalysts for water splitting are proposed. [ABSTRACT FROM AUTHOR]

Catalytic crackingof hydrocarbon fuels is an effective way tocool aircraft materials under hypersonic flight. Pseudohomogeneouscatalysis is an alternative to overcome the problems of traditionalcatalyst coatings. Herein, we employed the Brust–Schiffrinmethod to synthesize Pt and Pd nanoparticles (NPs) using oleylamineas the protecting ligand. The particle size can be controlled by tuningthe ratio of protecting ligand, and uniform NPs can be obtained atan oleylamine/NP molar ratio of 2, with Pt and Pd NPs of 1–3and 2–5 nm, respectively. IR and TG characterizations confirmedthat the amine group of oleylamine is chelated on the metal surfacewhereas the hydrophobic carbon chain is exposed in the hydrocarbonfuel. As a result, the NPs are highly dispersible in jet fuel JP-10without any precipitation after standing 12 months, providing thepossibility of pseudohomogeneous catalysis. Suspensions containingPt and Pd NPs (50 ppm) exhibited markedly enhanced cracking performance,with cracking conversions, gas yields, and heat sinks at 680 °Cthat were, respectively, 4.5, 4.4, and 1.3 and 3.1, 3.6, and 1.2 timesof pure JP-10. In particular, Pt NPs can reduce the onset temperatureof the cracking reaction from 650 to 600 °C. This work demonstratesthe potential of fuel-dispersible NPs in hypersonic applications. [ABSTRACT FROM AUTHOR]

Proton exchange membrane water electrolyzer (PEMWE) technology is of interest in the context of electrocatalytic hydrogen generation from renewable energies. It has the benefits of immediate response, higher proton conductivity, lower ohmic losses, and gas crossover rate. One key step toward to large‐scale application, is the development of highly efficient, durable, and compatible anodic oxygen evolution electrocatalysts in acidic media to decrease the usage of expensive and scarce precious metals. Within this scenario, an in‐depth understanding of oxygen evolution reaction mechanisms including the adsorption evolution mechanism and lattice oxygen evolution mechanism is first provided to aid development of innovative materials and elucidate the origin of catalyst degradation. Second, recent progress in the development of oxygen evolution electrocatalysts in acid media is reviewed with an emphasis on the underlying structure–performance relationships. Third, the current application status and research progress in PEMWEs along with representative examples are discussed. Last, the remaining challenges and promising insights are proposed to inspire future studies on the development of hydrogen production technology from renewable energy. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Non‐oxidative ethane dehydrogenation is a promising route to produce ethene. Herein, PtSn supported catalysts were investigated to achieve better ethane dehydrogenation performance by introduction of different Zr promoters, i.e., framework Zr and ZrO2, to mesoporous MCM‐41. In‐situ XRD, TEM and CO chemisorption show that aggregation of metal particles and phase segregation of Pt3Sn to Pt and PtSn3 at high temperature occur for PtSn/M, leading to bad ethane dehydrogenation activity. Strong interaction between ZrO2 and PtSn species, as proved by XPS, results in restrained metal particles, which promotes the initial reactivity. However, Pt phase generated on surface is disadvantageous for the desorption of produced ethene as indicated by CO‐IR and C3H6‐TPD, and pyridine‐IR and NH3‐TPD indicate strong acidity generated. Both deactivate the catalyst rapidly by deep dehydrogenation and coking. Moderate interaction between PtSn species and Si‐O‐Zr with much weaker acidity is formed when framework Zr is incorporated into MCM‐41, which benefits the dispersion of metal particles, formation of Pt3Sn/Pt species and stabilization of metal species from phase segregation. Outstanding initial ethane conversion and ethene selectivity of ca. 99% were achieved for the optimal PtSn/ZrM, which is more coking‐tolerant and stable by generating graphitic carbon mainly on support instead of active metals. [ABSTRACT FROM AUTHOR]

[Display omitted] • Au@Pt decorated Zn-CdS composites are fabricated for promoted charge separation. • Photodeposition leads to formation of Au-S bond and act as charge transfer channel. • The composites show synergetic effect of SPR and charge transfer channel. • Surface Pt serves active sites for rapid surface reaction. • Au@Pt/Zn-CdS exhibits lower charge transfer resistance and higher PEC activity. Photoelectrochemical (PEC) water splitting is a promising approach to solve the current energy and environmental crises. Herein, we developed a "one stone, two birds" strategy to construct Au@Pt decorated ZnO/CdS heterojunctions (ZCAP) with Au-S bond and surface plasmon resonance (SPR) effect for promoted PEC water splitting. The optimized ZCAP structure exhibited the highest photocurrent density of 4.23 mA/cm2 at 1.23 V vs. RHE and hydrogen evolution rate of 72.3 μmol·cm−2·h−1, which is magnitude higher than pure ZnO. In-depth investigations indicate that SPR effect can afford hot electrons, whereas Au-S bonds over interface act as transmission bridge for facilitated electron transfer, the synergy of them achieves efficient charge separation and light utilization. Meanwhile, surface Pt nanoparticles serve as active sites for rapid charge transfer and promoted surface reaction. This article illustrates that the synergy of SPR and electron transfer bridge is an efficient strategy for promoted PEC performance. [ABSTRACT FROM AUTHOR]

WO 3 has been recognized as a promising photoanode for the conversion of solar energy to hydrogen energy through photoelectrochemical water splitting. Herein, Zn-WO 3 nanorod arrays were synthesized by a two-step solvothermal method and then decorated with FeOOH and CoOOH dual co-catalysts layer through electrodeposition. Characterizations confirm the presence of abundant surface oxygen vacancies in Zn-WO 3 , leading to the increase of carriers with high mobility and thus improving the separation (from 63.7% to 92.0%) and injection (from 61.9% to 95.3%) efficiency of carriers. Meanwhile, the dual co-catalysts layer accelerates the transfer of the hole at the interface and inhibits the photocorrosion. Consequently, the optimal 9-Zn-WO 3 -Fe/Co exhibits the photocurrent of 3.63 mA/cm2 at 1.23 V vs. RHE, which is 90.7% of the theoretical value of WO 3 (ca. 4.0 mA/cm2). This work constructs a highly efficient and stable WO 3 photoanode by an integration strategy of transition metal doping and dual co-catalysts modification. [Display omitted] • A facile strategy to prepare Zn-doped WO 3 with dual co-catalysts is developed. • Multiple characterizations confirm the introduction of surface oxygen vacancies. • Effective carrier separation and transfer are achieved through the bulk and surface modification of WO 3. • The photocurrent density of 9-Zn-WO 3 -Fe/Co reaches 90.7% of the theoretical value of WO 3. [ABSTRACT FROM AUTHOR]

The work function of BiVO 4 is modulated from smaller to larger than that of PCN by controlling the oxygen vacancy, which switches the direction of interfacial band bending in BiVO 4 /PCN heterojunction. Accordingly, the photoinduced charge transfer mechanism is changed from type-II to direct Z-scheme for superior solar-driven pure water splitting. [Display omitted] Nature-inspired artificial Z-scheme photocatalyst offers great promise in solar overall water splitting, but its rational design, construction and interfacial charge transfer mechanism remain ambiguous. Here, we design an approach of engineering interfacial band bending via work function regulation, which realizes directional charge transfer at interface and affords direct Z-scheme pathway. Taking BiVO 4 as prototype, its oxygen vacancy concentration is reduced by slowing down the crystallization rate, thereby changing the work function from smaller to larger than that of polymeric carbon nitride (PCN). Consequently, the photoinduced charge transfer pathway of BiVO 4 /PCN is switched from type-II to Z-scheme as evidenced by synchronous illuminated X-ray photoelectron spectroscopy (XPS) and femtosecond transient absorption spectroscopy. Specifically, the direct Z-scheme BiVO 4 /PCN shows superior photocatalytic performance in water splitting. This work provides deep insights and guidelines to constructing heterojunction photocatalysts for solar utilization. [ABSTRACT FROM AUTHOR]

[Display omitted] • A piezotronic ZnO homojunction via defects modulation is designed. • The unique ZnO-based photoanode has piezoelectric effect and p-n homojunction. • This homojunction can avoid lattice mismatching and suppress carrier recombination. • The piezo-phototronic effect can enhance electric field of space charge region. • The piezo-photoelectrochemical activity is 2.1-times higher than pure ZnO. Homojunction is a viable alternative strategy to realize excellent charge separation for enhancing photoelectrocatalytic performance. However, the feasible regulation of the homojunction interface remains challenging. Herein, a ZnO n-p homojunction with the piezotronic effect is constructed via an in-situ solvothermal method for enhancing photoelectrocatalytic activity. ZnO nanorods are transformed from n-type to p-type ZnO nanoparticles with zinc vacancies, leading to the n-p homojunction. The optimal NPZ-36 exhibits a superior photocurrent density of 1.56 mA/cm2 at 1.23 V vs. RHE and a high incident photon to current conversion efficiency of 75 % at 360 nm. Impressively, with the merits of inherent piezoelectric and photocatalytic properties of wurtzite ZnO, the piezoelectric-enhanced photoelectrochemical activity originates from the simultaneous promotion of bulk charge transfer and interfacial charge separation in ZnO n-p homojunction. The photocurrent density of NPZ-36–900 can reach to 2.02 mA/cm2 under the stirring rate of 900 rpm, which is 2.1 times higher than that of pure ZnO photoanode. [ABSTRACT FROM AUTHOR]

Abstract: The shape evolution and control in the Brust–Schiffrin synthesis of Au nanoparticles (NPs) is presented in this work. Different from the current wisdom, Au NPs undergoes a time-dependent shape evolution. At the beginning, small spherical NPs are produced as reported before. With prolonged time, however, big NPs with many thermodynamically unfavored shapes such as triangle and truncated triangle are formed. And they are ultimately transferred into spherical shape bigger than the original NPs. It is suggested that the shape evolution is a kinetic-to-thermodynamic control process, during which, well-defined triangular plates are produced considerably by tuning the types of protecting ligands. This reveals the potential of fabricating not only size but also shape controllable metal NPs using the popular Brust–Schiffrin synthesis. [Copyright &y& Elsevier]