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The mechanical properties of composites are closely related to the interfacial behavior, especially under the hygrothermal circumstance. A catalytic sizing agent of titanium epoxy is designed to enhance interfacial, mechanical, and anti-hygrothermal properties of high modulus carbon fiber (HMCF)/cyanate ester composites simultaneously. The mechanisms of interface enhancement and low hygroscopicity of composites are investigated. The titanium epoxy is synthesized and its catalytic effect on the curing of cyanate ester is proved. The interfacial properties of HMCF composites with catalytic sizing agents are improved to 95.5 MPa, which is attributed to the interphase with high crosslinking density and sufficient triazine rings and oxazolidinone structure due to preferential curing induced by interfacial catalysis, stimulating the smooth transition of interphase modulus. Further, the formed interphase exhibits few interface defects and low content of hydroxyl groups, which changes the moisture diffusion path and reduces saturated water absorption of composites to only 0.36 %, resulting in the release of interfacial wet stress concentration and high retention of mechanical properties in hygrothermal environment. The resultant composites with high stiffness, excellent temperature resistance, superior dimensional stability and low moisture absorption are expected to be applied to high-orbit space, aerospace, precision instruments. [Display omitted] • The interfacial, mechanical, and anti-hygrothermal properties of composites are improved via catalytic sizing agents. • Catalytic sizing agents induce preferential curing of resin at the interface. • Catalytic sizing agents stimulate the smooth transition of modulus and increase IFSS. • The interphase with high interfacial adhesion and low hygroscopicity changes the moisture absorption path in composites. [ABSTRACT FROM AUTHOR]

The selective conversion of biomass-derived γ-valerolactone (GVL) to alternative green transportation fuels with high selectivity through a one-step synthesis process remains very challenging. The current procedures for GVL conversion to liquid fuels suffer from low selectivity or multiple operation steps with high energy consumption. Herein, we reported a simple and efficient way for the one-step synthesis of pentane fuel from GVL over the designed Co/HZSM-5 bifunctional catalyst in a single fixed-bed reactor under mild reaction conditions. The excellent catalytic performance of 99.9% conversion of GVL with 93.5% selectivity to pentane fuel and good stability for 100 h on stream was obtained. Combined experimental and theoretical studies demonstrated that the synergetic effect of interfacial active sites between metallic Co0 and proton acids of HZSM-5 is crucial for the high catalytic performance via providing a spontaneous carbonyl carbon–oxygen single bond cleavage path of GVL toward the selective synthesis of targeted pentane fuel through a series of subsequent reactions such as hydrogenation and hydrodehydration. [ABSTRACT FROM AUTHOR]

Although considerable efforts have been made in transforming carbon dioxide into high value‐added products, it still remains a big challenge to convert CO2 to CH4 directly at low temperature. Here, we report transition metals (including Fe, Co, Cr and Mn) modified Ni catalysts supported on Al2O3−ZrO2 via a single‐step sol‐gel method for low temperature CO2 methanation. Specially, incorporation of Mn metal into the Ni/Al2O3−ZrO2 catalyst was the most beneficial to the reduction and dispersion of NiO particles on the surface of Al2O3−ZrO2 composite support in comparison to other transition metals such as Fe, Co and Cr, which promoted the formation of active metallic Ni sites. Furthermore, the addition of Mn promoter facilitated the formation of surface oxygen vacancies, which combined with more metallic Ni active sites, thus improving the low‐temperature CO2 methanation performance significantly. An optimized Ni−Mn/Al2O3−ZrO2‐1 catalyst exhibited a superior CO2 conversion of 78 % with CH4 selectivity almost 100 % at a lower temperature of 300 °C without any deactivation in the long term 100 h reaction, which presented a potential industrial application for CO2 methanation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Single Cu atoms catalyst of Cu@UiO-66-(COOH) 2 was designed and synthesized. • High performance of LA hydrogenation to GVL was achieved via CTH route. • The defective sites in MOF facilitated the stabilization of Cu atoms. • The atomic dispersion of Cu and carboxyl group contributed to the high performance. Single-atom catalysts (SACs) have received great interests due to their high atomic utilization efficiency and unique electronic properties of active center atom. Here we reported a single-atom catalyst, Cu@UiO-66-(COOH) 2 , prepared by a simple, facile, and efficient solvothermal strategy, where Cu atoms were coordinated to the defect sites of secondary building units (SBUs) in a Zr-based metal–organic framework (MOF) UiO-66-(COOH) 2. The single-atom Cu@UiO-66-(COOH) 2 catalyst exhibited high activity for biomass derived platform chemical levulinic acid (LA) hydrogenation to γ-valerolactone (GVL) through catalytic transfer hydrogenation (CTH) process using isopropanol (IPA) as hydrogen donor under mild reaction conditions, where 96.7% GVL yield was achieved. The site isolation and uniform distribution of single Cu atoms combined with the aid of acid sites in MOF, attributing to the excellent catalytic performance for biomass upgrading. [ABSTRACT FROM AUTHOR]

[Display omitted] • One-step synthesis of gasoline fuels from γ-valerolactone was achieved. • Cu/HZSM-5 bifunctional catalyst with adjusting acidity and Cu loading content was designed. • The interfacial active sites composed of metallic Cu and proton acid of HZSM-5 determine the catalytic performance. • A spontaneous C O bond breaking path of γ-valerolactone was found. Direct synthesis of transportation liquid fuels from renewable biomass-based resources via γ-valerolactone (GVL) is a highly attractive but challenging target. The current conversion of biomass-derived GVL to liquid fuels suffers from low selectivity or multiple operation steps with high energy consumption. Herein, we reported a simple and efficient way for the high-selective conversion of GVL into gasoline fuels over designed Cu/HZSM-5 bifunctional catalyst in a single fixed-bed reactor. The excellent catalytic performance of 99.9 % conversion of GVL with 85.3 % selectivity to C 5+ hydrocarbons (mainly C 5 -C 12) and good stability were obtained. We demonstrated that the interfacial sites composed of metallic Cu and proton acid of HZSM-5 played a key role in determining the performance via providing a spontaneous C O bond breaking path of GVL, facilitating the formation of pentene intermediate that could be further converted to gasoline fuels through a series of aromatization, alkylation and oligomerization reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • γ-Valerolactone converting to butene was achieved. • Amorphous SiO 2 -Al 2 O 3 catalyst with adjustable acidity was prepared. • Lower acid sites facilitated the decarboxylation of pentenoic acid. • A two-stage integration system was developed for converting GVL to gasoline. γ-Valerolactone (GVL) as a sustainable platform compound could be converted to renewable fuels and chemicals, whereas directly converting GVL to target products remains still the challenge. In this work, we report an amorphous SiO 2 -Al 2 O 3 catalyst with adjustable acidity, which presented an excellent selectivity of 97.5 % butene at GVL conversion of 99.5 %, and remained an outstanding stability for 50 h. Appropriate weak and strong acid sites were the key for the ring-opening of GVL. Lower acid sites facilitated the decarboxylation of pentenoic acid (PEA), while higher acid sites promoted the cracking of PEA. Besides, a two-stage integration system was developed for converting GVL to C 5 + hydrocarbons via butene intermediate, giving a good yield of 57.6 % C 5 + hydrocarbons via combining the SiO 2 -Al 2 O 3 catalyst with nano-HZSM-5 together. [ABSTRACT FROM AUTHOR]

• Ni-Co synergetic effect promotes the ring-opening reaction significantly. • The presence of Ni in CoAl oxides restrains the growth of metal particles. • The adsorption configuration of furfuryl alcohol affects the products distribution. 1,5-pentanediol (1,5-PeD) is a value-added chemical that can be produced from furfuryl alcohol (FFA) via selective scission of C O bond coupled with following hydrogenation reaction. In this work, a series of hydrotalcite-derived Ni-Co-Al catalysts with different Ni/Co ratios were evaluated for FFA upgrading to 1,5-PeD at a temperature range of 413–473 K and hydrogen pressure from 2 to 5 MPa. The catalytic performance and reaction products distribution were found to be highly sensitive to the Ni/Co ratio in the catalysts as well as reaction conditions. The highest catalytic activity was achieved with the Ni-Co-Al catalyst at a Ni/Co atomic ratio of 1:11 (Ni 1 Co 11 Al), which attained a 1,5-PeD yield of 42.5 % after 4 h of reaction. The presence of Ni in the Ni 1 Co 11 Al catalyst could significantly improve the BET surface area and suppress the growth of metal nanoparticles, leading to its superior catalytic stability in 5 runs. According to the characterization results, it was supposed that hydrogen spillover occurred from the surface of Ni to that of Co species, which was expected to enhance the hydrogen adsorption/activation capability and surface H concentration. The rapid H transfer was beneficial to the hydrogenolysis of furan ring and in situ hydrogenation of reaction intermediates, thus greatly facilitating the activity of the catalyst. Based on the experimental and characterization results, a plausible reaction mechanism was proposed for the selective generation of 1,5-PeD from FFA over the Ni 1 Co 11 Al catalyst. The results attained in this paper demonstrated the possibility of using non-precious mixed metal catalyst for FFA upgrading, and could provide useful insights for the design of efficient catalysts. [ABSTRACT FROM AUTHOR]

Achieving precise selectivity control towards the sustainable production of biofuels and chemicals in biomass resources valorization via selective C-O bond activation is an important but challenging target. Herein, a selective conversion strategy of lignocellulosic-derived γ-valerolactone (GVL) using MFI-type HZSM-5 zeolite-mediated Co-based synergetic catalysts is reported. The as-synthesized Co@HZSM-5 catalyst with highly dispersed and stable Co nanoparticles inside microcrystal enables exceedingly high selectivity for the valeric biofuel production from GVL, whereas the zeolite-supported Co/HZSM-5 catalyst exhibits a selectivity switching towards pentane biofuel under otherwise identical conditions. This selectivity difference stems from the diverse synergetic catalysis between metallic Co and acidic HZSM-5 support of Co@HZSM-5 versus Co/HZSM-5 in GVL upgrading. Theoretical calculations further demonstrate the distinct ring C-O bond strength of GVL under these two Co chemical microenvironments, which is crucial to tune the C-O bond activation modes in GVL ring-opening, affording a flexible selectivity switching toward valeric- or pentane-oriented reaction channels. [Display omitted] • Highly dispersed and stable Co nanoparticles was finely encapsulated in HZSM-5. • Selectivity switching of valeric/pentane biofuels from GVL upgrading was achieved. • Diverse Co-acid synergetic effects under two Co chemical environments were found. • Well-controlled ring C-O bond activation mode in GVL ring-opening was achieved. [ABSTRACT FROM AUTHOR]

This work aimed to investigate the feasibility of using metal-modified (Fe, Co, Ni, Cu, Zn, Ga) HZSM-5 zeolite as catalysts for high-value monocyclic aromatic hydrocarbons production via lignin catalytic pyrolysis in a two-stage fixed bed reactor. The structure-performance relationship of the catalysts was revealed based on the catalytic reaction testing results along with the acidity and textural properties obtained via systematic physicochemical characterization techniques, thus guiding the selection of the best modification metal and the optimal loading amount. As demonstrated, the 1 wt% Co modified HZSM-5 (1%Co-HZ) exhibited relatively slight coverage effect on the active sites, while increased the mesoporous surface area and average pore size of the parent HZSM-5 zeolite. Consequently, enhanced mass-transfer efficiency was attained by the 1%Co-HZ catalyst, which achieved the highest monocyclic aromatic hydrocarbons content (29.3%) among all the investigated metal-modified HZSM-5 catalysts. In addition, the Co modified sample showed better resistance to carbon deposition than that of the unmodified one. Overall, 1%Co-HZ can be used as an effective catalyst for monocyclic aromatic hydrocarbons production in lignin catalytic pyrolysis. • Direct conversion of lignin into monocyclic aromatic hydrocarbons was demonstrated. • Increased mesoporous surface area and high acid amount were attained on 1%Co-HZ. • The 1%Co-HZ catalyst achieved high production of C7-C9 aromatic hydrocarbons. [ABSTRACT FROM AUTHOR]