查看更多>>摘要：High-valence metals such as Mo, W, etc. can modulate the adsorption and desorption energy of 3d-metal-based electrocatalysts, favorable for the intrinsic activity for hydrogen evolution reaction (HER) at large current density. However, the facile and exact incorporation of high-valence metals remains a big challenge. Herein, a metallic MoOx layer has been designed via anodization of Mo foil to achieve high-valence Mo doping into CoP to finally form the real active component Mo-CoP for HER. The activated metallic MoOx layer provides an optimized Mo doping into CoP, obtaining Mo-CoP/MoOx with~& nbsp;226 mV (alkaline) and~& nbsp;275 mV (acidic) at > 2000 mA cm(-2). Meanwhile, in-situ grown F-Mo-CoP/MoOx controllable treated by fluoroaniline possesses enhanced the structural robustness of Mo-CoP/MoOx with long-term stability at large current density. This work not only illustrates the facile approach of regulating electron structure via high-valence metal doping, but it also provides the rational strategy for enhanced stability for industrial applications.
查看更多>>摘要：The production of furfuryl alcohol (FFA) from biomass-derived furfural (FF) via selective hydrogenation is challenging due to the diverse unsaturated groups. Herein, a novel hydrotalcite-derived Pt-based catalyst was synthesized to catalyze the selective hydrogenation of FF to FFA in water. Within 2 h at 303 K and 1.5 MPa H-2, 99.9% conversion of FF with > 99% selectivity to FFA was obtained while the TOF being 204.6 h(-1) and the E-a being 12.8 kJmol(-1). These results were accounted for by the 2D layered double hydroxides structure of hydrotalcite, which contributed to the high dispersion and effective reduction of Pt species, and the selective adsorption of the aldehyde group of FF on the catalyst, combined with the rapid desorption of the FFA produced. This guaranteed selective and stable hydrogenation over time, with up to four cycles ensured.
查看更多>>摘要：Formic acid (FA), as a safe and renewable hydrogen storage material, attracts extensive attention. Herein, an efficient catalyst Au0.35Pd0.5Ir0.15 nanoalloy supported on NH2-N-rGO has been successfully synthesized and applied for hydrogen generation from FA. It is found by density function theory (DFT) calculation that addition of Ir into AuPd alloy can change the initial adsorption configuration of HCOOH* and thus reduce the energy barrier of rate determining step (RDS) of FA dehydrogenation. As a result, Au0.35Pd0.5Ir0.15/NH2-N-rGO displays 100% conversion, 100% selectivity even after 150 days for FA dehydrogenation at 298 K, and the initial turnover frequency (TOF) can reach the recorded value (12781.2 h(-1)) without any additives. More interestingly, it is proved to be a universal method to design the effective catalysts for hydrogen generation from FA by the high activities of other tri-metallic alloys with addition of other high gamma elements (such as Pt, Rh, and Ru).
查看更多>>摘要：Understanding the basic principle of Pd-based bimetallic catalysts design is essential in CO2 hydrogenation to formate. In this work, Cu partially replaced the bivalence position in MgAl hydrotalcite structure was developed for achieving the highly confined Cu species, whose interaction with Pd species was systematically studied and compared with the traditional co-impregnation or stepwise impregnation method. The stable and maximum formate formation rate of 12.8 mmol/h/g(metal) was obtained on Pd-0.4@CuMgAlOx catalyst under 100 degrees C, 4.0 MPa, H-2/CO2 ratio of 3, being about double of the sum of formate production rate over the monometallic Cu and Pd catalysts. Strong synergetic interaction between Pd and the confined Cu species was observed with Cu/Pd atomic ratios of 14-181. Extensive characterization using TEM, XPS, XANES, coupled with kinetic study and in situ DRIFTs analysis revealed that the superior performance of Pd-0.4@CuMgAlOx was attributed to the confined PdCu nanoparticles with electron-rich PdCu surface.
NSTL
Elsevier