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Photocatalytic conversion of renewable biomass‐derived aldehydes into high‐valued chemicals is a promising path to meet the growing demand for clean energy and chemical resources. However, the approach still faces challenges, such as limited reaction types and low utilization rates due to the complex functional groups and involved polytropic reaction. In the present work, we developed a catalyst of Pt nanoparticles (Pt NPs) supported on a NiO–In2O3 bimetallic oxide (denoted as Pt/NiInOx) for photocatalytic hydrogenation of furfural (FAL) to furfural alcohol (FOL). Owing to the excellent band structure and efficient internal charge transfer on the p–n heterojunction in the catalyst, the highest 99.9% yield to FOL was obtained over the Pt/NiInOx under a light‐emitting diode (LED) light at low temperatures as 273 K. The combination of ·H dissociated from H2 and oxygen vacancy work synergically to adsorb, activate, and converse C=O to the C–O group. The photocatalytic system presents a highly efficient approach for the rapid hydrogenation of biomass‐based aldehydes under a low LED light radiation intensity at a low temperature. The work is expected to serve as an important reference in constructing bimetallic oxide‐supported active metals, enabling efficient separation of photogenerated electrons and holes, and offering oxygen vacancies in various photocatalytic reactions. [ABSTRACT FROM AUTHOR]

The development of highly active and selective photocatalytic systems for the oxidation of benzylic C(sp3)–H and C(sp3)–OH to C＝O bonds under solvent-free conditions with molecular oxygen as an oxidant is attractive and challenging. In this study, a carbon- and PdO-doped Nb2O5-based catalyst (PdO/C–Nb2O5) was designed and synthesized. This photocatalyst showed excellent solvent-free aerobic photocatalytic performances for two typical oxidation reactions of benzylic C(sp3)–H and C(sp3)–OH to C＝O compounds. It was found that the doping of carbon and PdO in Nb2O5 can modify its surface electrons, increase oxygen vacancies, and change the positions of its valence band and conduction band. Besides, the kinetic study showed that the oxidation of C–H in ethylbenzene to C–OH is the rate-limiting step in the two-step oxidation of ethylbenzene to acetophenone. Moreover, a photocatalytic reaction mechanism was proposed based on these experiments. In addition, the solvent-free aerobic photocatalytic oxidation system showed a good substrate tolerance for benzylic C(sp3)–H and C(sp3)–OH compounds with different substituents to the corresponding ketones and aldehydes. [ABSTRACT FROM AUTHOR]

Imines are vital intermediate chemicals applied in organic synthesis, pharmaceuticals, and materials science. It is desirable but challenging to explore a green photocatalytic system, especially solvent-free photocatalysis, for the synthesis of imines from amines with molecular oxygen as an oxidant under mild reaction conditions. In the present study, a ternary CdS/Ag/BiVO4 Z-heterojunction photocatalyst was designed and prepared for the photocatalytic oxidative coupling of benzylamine to N-benzylidenebenzylamine. Under solvent-free conditions, a yield of 92% of N-benzylidenebenzylamine with a selectivity of 99% was achieved over CdS/Ag/BiVO4 in neat benzylamine with dioxygen as an oxidant at room temperature and ambient pressure. In the Z-scheme electronic transmission system, CdS worked as a reductive photocatalyst, while BiVO4 acted as an oxidative photocatalyst. The oxygen vacancies in the catalyst and Ag nanoparticles in the catalyst with their plasmonic effect boosted light absorption, enhancing charge migration and photogenerated electron–hole separation on the contact interface. A photocatalytic mechanism was proposed based on controlled experiments. The catalyst exhibited good stability for five cycles, and the catalyst can be applied for the oxidative coupling of various amines to imines. This work provides a strategy for the rational design of photocatalytic oxidative coupling of amines to imines. [ABSTRACT FROM AUTHOR]

The advancement of cost-effective and highly efficient electrocatalysts for hydrogen evolution is pivotal in fostering the progress of clean energy technologies. In this study, we present a reforming approach aimed at facile fabrication of the Cr-CeO2/rGO electrocatalyst. This involves incorporating a limited quantity of reduced graphene oxide (rGO) to serve as a conductive scaffold for CeO2 nanocrystals (NCs) while also introducing Cr, a transition metal, as an active dopant. It is found that the introduction of Cr and rGO induces charge transfer, leading to enhanced electrical conductivity and the creation of additional active sites on the nanocomposite surface. The synergy between rGO and CeO2, along with Cr doping in CeO2, significantly improves HER performance. The representative sample of the Cr(5%)-CeO2/rGO catalyst demonstrates a low overpotential of 83 mV at a current density of 10 mA cm–2, a low Tafel slope of 81 mV dec–1, and excellent stability under alkaline conditions. Significantly, this value of overpotential is reduced by 81 and 127 mV compared to those of the CeO2/rGO nanocomposites and the pristine CeO2 NCs. Theoretical density functional theory calculations additionally validate the phenomenon of charge transfer and improved HER properties, with Cr-CeO2 displaying a favorable Gibbs free energy (ΔGH*) for H* adsorption. This study offers novel insights into the design of precious metal electrocatalysts featuring functional interfaces and a wealth of active sites, holding great promise for industrial applications in clean energy conversion and storage. [ABSTRACT FROM AUTHOR]

In this review, we summarize the important progress in the electroreduction of N2 to NH3 using state-of-the-art two-dimensional (2D) electrocatalysts. We expound on several reaction mechanisms of the nitrogen reduction reaction (NRR) and report recent experimental progress regarding these unique 2D NRR electrocatalysts. In addition, some concepts recently proposed from high-throughput computations and machine learning are described. By building on a detailed understanding of the process of N2 conversion to NH3 on 2D electrocatalysts, novel 2D materials that could potentially serve as viable NRR electrocatalysts are presented. Future perspectives and challenges of N2 electrolysis using 2D materials are also discussed. [ABSTRACT FROM AUTHOR]

Ammoxidation of alcohols is a promising cyanide-free strategy for the synthesis of organic nitriles. It is desirable but challenging to conduct nitrile synthesis over a heterogeneous metal-free catalyst with aqueous ammonia as a nitrogen source and molecular oxygen as an oxidant. In the present work, an Se,P,N-tridoped carbon nanomaterial (Se,P,N/CN-900) was prepared and used as a metal-free catalyst for the direct ammoxidation of alcohols to nitriles with aqueous ammonia and molecular oxygen. The synergistic effect was revealed for the highly efficient catalytic performance of the tridoped carbon catalyst. The present catalyst showed good stability, and various (hetero)-aromatic alcohols can be converted to the corresponding nitriles with high yields. To the best of our knowledge, this is the first work to achieve ammoxidation of alcohols to nitriles with a high efficiency over multidoped carbon materials. [ABSTRACT FROM AUTHOR]

Oxygen-containing organics, which are generated from the selective oxidation of their corresponding hydrocarbons, have high value in the chemical and pharmaceutical industries. However, their oxidation reactions are very challenging as the products are more active than the substrates, especially for the oxidation of cyclohexane (CHA). Herein, we focused on the one-step preparation of Bi2WO6 with double active sites of tunable metallic Bi and oxygen vacancies (OV–Bi/Bi2WO6) by a facile solvothermal treatment. Then, OV–Bi/Bi2WO6 was used as an efficient photocatalyst for the partial oxidation of CHA to cyclohexanone (CHA-one) for the first time in air as an oxidant under solvent-free and room temperature conditions. The Bi : Bi2WO6 ratio in the as-prepared OV–Bi/Bi2WO6 heterojunction could be tailored from 0.08 to 8.43 by controlling the solvothermal temperature, and the synergistic effect between DMF and EG could increase the reduction of MDF/EG and promote the production of Bi. Moreover, OV–Bi/Bi2WO6-160 yielded 4.4 and 8.8 times more CHA-one (128.8 μmol) than pure Bi2WO6 and metallic Bi, respectively, and achieved 93.6% selectivity to CHA-one in air as an oxidant under solvent-free conditions. The results revealed that the highly enhanced photocatalytic activity was mainly attributed to the superior specific surface area, outstanding photo-absorption, abundant oxygen vacancies, and efficient electron–hole separation. Moreover, for the unique double active sites in OV–Bi/Bi2WO6, oxygen vacancies can enhance the adsorption and activation capacity of Bi2WO6 for O2, while metallic Bi can improve the adsorption and activation capacity of Bi2WO6 for CHA. Meanwhile, OV–Bi/Bi2WO6 also exhibited excellent durability due to the strong interaction between metallic Bi and Bi2WO6. The present work provides a flexible approach for tailoring the Bi : Bi2WO6 ratio and outlines an effective method for producing CHA-one from CHA under mild conditions. [ABSTRACT FROM AUTHOR]

Chemical utilization of CO2 is one of the fundamental strategies to synthesize value-added chemicals and reduce the CO2 emission. N-formyl-1,2,3,4-tetrahydroisoquinoline derivatives (FTHIQs) are important chemicals for the synthesis of medical intermediates and alkaloids. N-formylation of isoquinoline derivatives (IQs) with CO2 is an ideal protocol to synthesize the FTHIQs and utilize the CO2 source. In the present work, we prepared a heterogeneous Ru/ZIF-8 catalyst with a Ru loading of 2 wt% by a simple impregnation method and assessed its performances in the N-formylation of IQs and CO2 with H2. The Ru/ZIF-8 catalyst offered high IQ conversion of 98% and FTHIQ selectivity of 93% in the reaction under relatively mild conditions (150 °C, 2 MPa CO2, and 6 MPa H2). The catalyst possessed good universality and reusability, showing a potential in wide application of N-formylation of highly unsaturated nitrogen-containing isoquinolines. [ABSTRACT FROM AUTHOR]

A solvothermal route was developed to synthesize hierarchical TiO2 nanoflowers with tunable morphology, macroporous and mesoporous structure, and larger surface areas by varying the ratio of N,N-dimethylformamide to isopropyl alcohol without using surfactant and template. Morphology and microstructure, textural, crystalline, optical and photoelectric properties were characterized to investigate thoroughly the correlation of features and photoactivity of catalysts. The photoactivity was evaluated for the degradation of phenol through analyzing the phenolic compounds. The catalysts exhibited significantly high photocatalytic activity with the degradation rate of phenol of 95%, and the decrease of total organic carbon (TOC) was 82 ± 3% under ultraviolet radiation (UV) for 180 min at room temperature. Meanwhile, the excellent cyclic stability and regenerability were obtained during five cycles and continued illumination. The enhanced photocatalytic activity probably was attributed to larger surface areas, hierarchical porous structure, effective generation and separation of the charge carriers, and outstanding light-harvesting ability. [ABSTRACT FROM AUTHOR]

CO2 oxidative dehydrogenation of propane (CO2-ODHP) is a strategy of "two birds with one stone" to synthesize propylene and utilize CO2. However, the reaction is always conducted at high temperatures (>550 °C). In the present work, we have for the first time conducted the reaction at 270 °C under photothermal conditions over several BiOX (X = Cl, Br, I) nanocatalysts. Among them, the BiOI nanosheet catalyst exhibited the highest C3H6 formation activity of 282.6 μmol gcat−1 h−1 with 89% selectivity. The lattice oxygen species on the catalyst could catalyze propane dehydrogenation to propylene, and simultaneously, oxygen vacancies were formed. The oxygen vacancies are responsible for CO2 reduction to CO. In addition, the catalyst is facet-dependent, and the (001) facets are more active than the (110) facets. The present work successfully verifies the feasibility of photothermal catalytic CO2-ODHP over BiOI nanosheets and also provides a new insight to construct other facet-dependent dual-functional redox catalysts. [ABSTRACT FROM AUTHOR]

It is attractive but challenging to develop a non-noble metal-based photocatalytic system for the selective oxidation of benzyl alcohol to benzaldehyde under solvent-free conditions. Herein, a Z-scheme heterojunction photocatalyst of ZnO/C3N4 was designed and prepared. Under solvent-free irradiation conditions, benzyl alcohol can be exclusively oxidized to benzaldehyde with a yield of 99.8% and a formation rate of 16 633 μmol g−1 h−1 at room temperature. To the best of our understanding, the photocatalytic activity and selectivity of this oxidation process are much better than those reported for noble and non-noble metal-based photocatalyses. The water generated in the solvent-free oxidation process is revealed to disfavor the activity and selectivity. In addition, the mechanism of the title reaction is proposed. The present solvent-free photocatalytic system can be applied for the oxidation of benzylic, allylic, heterocyclic, and aliphatic alcohols to their corresponding aldehydes. [ABSTRACT FROM AUTHOR]

In this work, a fast and self-propagated carbonization (SPC) method to prepare phosphorus-doped carbon (PDC) and hybrid materials is proposed. PdZr/PDC prepared by the SPC method has good catalytic performance for both partial oxidation of benzyl alcohol to benzaldehyde and partial hydrogenation of phenol to cyclohexanone. The method has some obvious advantages, such as being simple and clean, and can be used easily for the large-scale preparation of the materials. [ABSTRACT FROM AUTHOR]

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The conversion of CO2 to C2H4, especially via the electrochemical CO2 reduction reaction (CO2RR), is one of the promising approaches for utilizing CO2 and producing important light olefins. Developing efficient catalysts is the key to realizing this conversion. In the present work, we have prepared several Cu–Zr bimetallic catalysts and assessed their performances in the CO2RR to C2H4 using an H-type cell. Among the prepared catalysts, the bimetallic Cu–Zr catalyst (denoted as ZrO2/Cu-Cu2O) with a Cu/Zr molar ratio of 7/1 could achieve a 62.5% faradaic efficiency of ethene (FEC2H4) with a high current density of 24 mA cm−2 at −1.28 V (vs. RHE) in 0.1 M KCl electrolyte. Characterization results indicated that the catalyst comprises ZrO2 nanoparticles (NPs) supported on Cu-Cu2O NPs. The in situ Raman tests showed that a *COOH intermediate was involved during the reaction. DFT calculation further confirmed that the *COOH intermediate was favorably generated on Zr sites, which could be transferred to the adjacent Cu+ sites to couple and form *OCCO (or 2*CHO) dimers at the interface between Cu and Zr species. The dimer was further reduced to C2H4 under the given conditions. The cooperation of the two components and interfaces resulted in the outstanding performance of the catalyst. We believe that the method to construct multicomponent interfaces to enhance FE and activity can also be used to design some other efficient catalysts for the CO2RR. [ABSTRACT FROM AUTHOR]

Photocatalytic CO2 reduction is a highly vital process for converting CO2 into valuable chemicals. However, the reaction always proceeds less efficaciously at low temperature. A combination of optical and thermal conditions is one of the feasible approaches to achieve the reaction with high efficiency and has gained much attention recently. In the present work, we prepared several Co–Cu–Mn trimetallic catalysts via a simple co-precipitation method, which were used in catalyzing photothermal CO2 reduction to hydrocarbons. The metal composition and reduction temperature of the catalysts had important effects on their structural and photoelectrical characteristics and adsorption behaviors, further resulting in diverse catalytic performances. Among the prepared trimetallic catalysts, Co7Cu1Mn1Ox(200), with a Co/Cu/Mn molar ratio of 7/1/1 and reduced at 200 °C in H2 for 2 h, could produce CH4 with an activity of 14.5 mmol gcat−1 h−1 in 10% CO2/30% H2/60% N2, and CH4 and C2+ hydrocarbons with the activities of 15.9 and 7.5 mmol gcat−1 h−1 in 25% CO2/75% H2, respectively. The present strategy for constructing trimetallic oxide catalysts for the photothermal reaction not only provides a highly active catalyst for CO2 utilization, but also offers a potential possibility for reducing the high temperature of conventional thermal reactions. [ABSTRACT FROM AUTHOR]

A number of metallocalix[n]arenes, where n = 4, 6, or 8, of titanium and vanadium have been screened for their ability to act as catalysts for the co‐polymerization of propylene oxide and CO2 to form cyclic/polycarbonates. The vanadium‐containing catalysts, namely [VO(L1Me)] (1), [(VO2)L2H6] (2), [Na(NCMe)6]2[(Na[VO]4L2)(Na(NCMe))3]2 (3), [VO(μ‐OH)L3/H2]2∙6CH2Cl2 (4), {[VO]2(μ‐O)L4[Na(NCMe)2]2} (5), {[V(Np‐tolyl)]2L4} (6) and [V(Np‐RC6H4)Cl3] (R = Cl (7), OMe (8), CF3 (9)), where L1H3 = methylether‐p‐tert‐butylcalix[4]areneH3, L2H8 = p‐tert‐butylcalix[8]areneH8, L3H4 = p‐tert‐butylthiacalix[4]areneH4, L4H6 = p‐tert‐butyltetrahomodioxacalix[6]areneH6, performed poorly, affording, in the majority of cases, TONs less than 1 at 90°C over 6 h and low molecular weight oligomeric products (Mn ≤ 1665). In the case of the titanocalix[8]arenes, {(TiX)2[TiX(NCMe)]2(μ3‐O)2(L2)} (X = Cl (10), Br (11), I (12)), which all adopt a similar, ladder‐type structure, the activity under the same conditions is somewhat higher (TONs >6) and follows the trend Cl > Br > I; by comparison the non‐calixarene species [TiCl4(THF)2] was virtually inactive. In the case of 10, it was observed that the use of PPNCl (bis[triphenylphosphine]iminium chloride) as co‐catalyst significantly improved both the polymer yield and molecular weight (Mn 3515). The molecular structures of the complexes [HNEt3]2[VO(μ‐O)L3H2]2∙3CH2Cl2 (4∙3CH2Cl2), [VO(μ‐OH)L3/H2]2∙6CH2Cl2 (4/) (where L3/H2 is a partially oxidized form of L3H4) and {(TiCl)2[TiCl(NCMe)]2(μ3‐O)2(L2)}·6.5MeCN (10·6.5MeCN) are reported. [ABSTRACT FROM AUTHOR]

The synthesis of benzyl alcohols (BAs) is highly vital for their wide applications in organic synthesis and pharmaceuticals. Herein, BAs was efficiently synthesized via hydroxymethylation of phenylboronic acids (PBAs) and paraformaldehyde over a simple RhPPh3 catalyst combined with an inorganic base (NaOH). A variety of BAs with the groups of CH3−, CH3O−, Cl−, Br−, and so on were obtained with moderate to good yields, indicating that the protocol had a good universality. Density functional theory (DFT) calculations proposed the Hayashi‐type arylation mechanism involved the arylation step of PBA and Rh(OH)(PPh3)2 catalyst to form Rh(I)‐bound aryl intermediates and the hydrolysis step of Rh(I)‐bound aryl intermediates and HCHO to generate BA product (the rate‐determining step). The present route provides a valuable and direct method for the synthesis of BAs and expands the application range of paraformaldehyde. [ABSTRACT FROM AUTHOR]