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A systematic study of Au‐promoted and unpromoted Pt/MgO/SBA‐15 catalyst is developed to separate the promoter effect from electron transfer effect between Au and Pt. Multi‐characterizations revealed that Au and Pt metals in these bimetallic catalysts mainly exist in the form of alloy, and the main role of Au is to reduce the size of AuPt alloy nanoparticles, thus enhancing the adsorption and activation of intermediate products. Through the optimization of various factors (including MgO content, Au/Pt molar ratio, reaction temperature and time), the Au1Pt2/MgO/SBA‐15 (0.05) catalyst exhibits excellent catalytic activity and glyceric acid selectivity for the selective oxidation of glycerol. Density functional theory calculation confirmed that the synergistic effect between Pt and Au active sites could facilitate the oxidation of primary hydroxyl group by promoting the activation of CH bond and the oxidation of aldehyde group. The results may give insights on designing effective Pt based bimetallic catalyst for selective oxidation of glycerol. [ABSTRACT FROM AUTHOR]

A Ni 1 Co 1 O x catalyst with lattice distortions was prepared by a modified hard template method. Elemental analysis shows that Ni tends predominantly to disperse on the surfaces of the nanoparticles. Under the optimum reaction conditions (80 °C, 20 h, and 1.5 g NaOH), Ni 1 Co 1 O x catalyst could exhibit optimum catalytic performance (78.5% conversion, 66.5% GLYA selectivity, and recycling for four times). • A lattice-distorted Ni 1 Co 1 O x catalyst was synthesized by a modified hard template method. • High selectivity toward glyceric acid was obtained on the Ni 1 Co 1 O x catalyst. • Electron transfer from Ni cations to Co cations results in the generation of surface oxygen vacancies. • The oxygen vacancies of Co and Ni species promote the oxidation of glycerol to glyceric acid. Developing cheap and highly efficient catalysts for the selective oxidation of glycerol to value-added carboxylic acids still remains a challenge. Here, non-noble-metal Ni–Co oxide catalysts with lattice distortions are reported for the first time as highly efficient and stable catalysts for the oxidation of glycerol to glyceric acid. The Ni 1 Co 1 O x catalyst, prepared by a modified hard template method, exhibits superior activity (1.5 × 10−3 s−1), excellent glyceric acid selectivity (66.5%), and good stability under mild conditions (80 °C, 1 MPa O 2). Multiple characterizations demonstrated that the nanosized Ni 1 Co 1 O x catalyst (2.3 nm) contains lattice distortion Ni–Co structures with nickel-rich surfaces. This morphology induces electron transfer from Co cations (mainly Co3+) to Ni cations (mainly Ni3+), resulting in the generation of surface oxygen vacancies. Density functional theory calculations and catalytic kinetics demonstrated that oxygen vacancies on Co species could improve glyceric acid selectivity by preventing the cleavage of C C bond, and oxygen vacancies on the Ni species could promote the activation of C H bonds, which results in the exceptional catalytic performance of Ni 1 Co 1 O x. The novel Ni–Co oxide catalyst with lattice distortions synthesized here may provide some guidance for the rational design of inexpensive and highly efficient catalysts for the catalytic oxidation of biopolyols. [ABSTRACT FROM AUTHOR]

Graphical abstract In-situ coating of SBA-15 with MgO was synthesized in one-step procedure to form the mesoporous solid bases. Then, the Pt nanoparticles were loaded by NaBH 4 reduction method. Subsequently, the Pt/MgO-SBA-15 catalyst was applied to the selective oxidation of glycerol to obtain C 3 products. Highlights • Novel hybrid Pt/MgO/SBA-15 catalysts were prepared. • The Pt nanoparticles was restricted in the channel of MgO/SBA-15. • The synergistic effect between Pt and MgO enhanced glycerol oxidation activity. • Oxygen active sites of MgO promoted the dehydrogenation reaction. Abstract Enhanced metal-support interaction is the key for selective oxidation of glycerol to value-added carboxylic acids. However, the rational control of interfacial properties still remains a significant challenge. In this work, we prepared hybrid Pt/MgO/SBA-15 catalysts for the facile oxidation of glycerol to glyceric acid in the absence of liquid alkalis. It was found that the confinement effect of SBA-15 leads to restricted Pt nanoparticles in the MgO/SBA-15 channel with a unique "strip" shape. Such a morphology and the strong electron coupling effect between Pt and MgO species synergistically enhanced glycerol oxidation over Pt-MgO sites. A volcanic-shaped relationship between Mg/Si ratio and catalytic performance was established experimentally, and the Pt/MgO/SBA-15 (0.1) catalyst showed excellent combined selectivity for C 3 products (glyceric acid, glyceraldehyde and dihydroxyacetone) with a remarkable turn over frequency (TOF) of 1671.2 h−1 higher than the reported catalysts under base-free conditions. Furthermore, density functional theory (DFT) calculations confirmed that the oxidation reaction could be promoted by oxygen defects of MgO sites, resulting in a reduction of the energy barriers for C H and O H activation. These insights may provide a new way to the supported solid base catalyst design and mechanistic study. [ABSTRACT FROM AUTHOR]

Tailoring the hydrodeoxygenation capacity via the regulation of the electronic structure of the active site is still a significant challenge for hydrogenation of oxygenated substrates. Herein, we report the highly efficient bimetallic CoNi/HAP catalysts to promote the catalytic transfer hydrodecarbonylation of methyl stearate to heptadecane. Multiple characterizations reveal that the CoNi alloy nanoparticles with fcc structure exhibit strong electron coupling effect and enhanced adsorption of methyl stearate, leading to the improvement of catalytic activity. Specifically, the introduction of Ni changes the reaction pathway from methyl stearate → octadecanol over the Co/HAP catalyst to methyl stearate → heptadecane over CoNi/HAP catalysts. In situ Fourier transform infrared spectra, reaction kinetics and density functional theory calculation show that the heptadecane is mainly generated through hydrodecarbonylation (-CO) rather than hydrodecarboxylation (-COO) because the C C bond cleavage of oxygenated intermediate (RCH 2 CO) is greatly facilitated over the Ni active site of electron reconstructed CoNi alloy nanoparticles. Finally, the Co 5 Ni 5 /HAP catalyst exhibits excellent conversion (99.4%), heptadecane selectivity (98.2%) and catalyst stability. These insights revealed here could pave the way for the rational development of catalyst with high catalytic performance in the catalytic transfer hydrogenation system of fatty acids/esters. The introduction of Ni strengthens the electron coupling effect of the CoNi alloy nanoparticles, and promotes the adsorption of MS/SA, resulting in the improvement of catalytic activity. During the hydrogenation process, Co metal active site promotes the formation of oxygen-containing intermediates before octadecanol, and the as-formed C C bond of the oxygenated intermediate (RCH 2 CO) tends to be activated on the Ni active site of CoNi alloy nanoparticles, leading to the high HP selectivity. Finally, the Co 5 Ni 5 /HAP catalyst exhibits excellent conversion (99.4%), heptadecane selectivity (98.2%) and catalyst stability. [Display omitted] • Bimetallic CoNi/HAP catalysts could promote the catalytic transfer hydrodecarbonylation of methyl stearate to heptadecane. • fcc -type CoNi alloy nanoparticles exhibit strong electron coupling effect and enhanced the adsorption of methyl stearate. • Reaction pathway of catalytic transfer hydrogenation of methyl stearate to heptadecane is greatly promoted. • C-C bond cleavage of RCH 2 CO intermediate is greatly facilitated over the surface of electron reconstructed CoNi alloy. • Excellent conversion and heptadecane selectivity were obtained on the Co 5 Ni 5 /HAP catalyst. [ABSTRACT FROM AUTHOR]

The reduction reaction of carbon dioxide (RR -CO 2) to CH 3 OH using metal catalysts can reduce the energy required by this process. In this study, we investigated the RR -CO 2 mechanisms with Cu-, Ni-, and Mn-doped carbon nanotubes (CNTs). The substitutional (doping with carbon atom) positions in CNTs are suitable sites for adsorbing Cu, Ni, and Mn metals. The reaction paths to the RR -CO 2 were investigated in the gas and solvent phases. The results demonstrated that the overpotential values with Cu-, Ni-, and Mn-doped CNT(8, 0) and CNT(6, 6) catalysts in the gas and solvent phases were lower than that obtained with metal catalysts in previous studies (−1.116 V). Thus, metal-doped CNT(8, 0) and CNT(6, 6) catalysts with low overpotentials could be applied in the RR -CO 2. • Potential of nano-structures to RR- CO 2 is examined. • Possible reaction mechanisms for CO 2 reduction to CH 3 OH are investigated. • Over potential of RR- CO 2 on nano-structures are lower than metal catalysts. • Nano-structures are proposed as efficient catalysts for RR- CO 2. [ABSTRACT FROM AUTHOR]