查看更多>>摘要：Substituting overall water splitting with simultaneous biomass upgrading and H-2 evolution has drawn tremendous attention due to the lower energy barrier and higher safety. Developing a cheap, efficient, and durable electrocatalyst with dual function is crucial to this novel coupling system. Herein, we propose the in-situ electrochemical tuning nonporous CoSx to hydrangea-like Co3O4 as a highly effective versatile electrocatalyst for the first time. Due to the defective structures and abundant electroactive sites, the Co3O4 catalyst achieved a complete conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) with 93.2% yield and 92.9% faradaic efficiency (FE), as well as a pure hydrogen evolution with 99.8% FE. Interestingly, it harvested a better performance with 95.8% FDCA yield for electro-oxidation of the more stable 2,5-bis(hydroxymethyl)furan (BHMF). Finally, a solar-driven integration reaction was constructed for the first time using the photovoltaic electrocatalysis (PVEC) of BHMF for the efficient and sustainable production of FDCA and H-2.
查看更多>>摘要：Photocatalysis provides a new avenue for organic synthesis, to which catalyst design at atomic level holds the key. Herein, the first case of ppm-level (39 ppm) Cu dopant based photocatalyst has been successfully constructed as Cu1Pd200/TiO2, in which Cu element dopes ultrathin Pd nanosheets (thickness of 2 nm) with atomic dispersion using TiO2 as the semiconductor host. The alcoholysis of styrene oxide, as a model reaction, can produce valuable beta-alkoxy alcohols, conventionally requiring corrosive strong acids or harsh reaction conditions. The presence of ppm-level Cu atoms in Cu1Pd200/TiO2 can boost alcoholysis with a quite high reaction rate of 176 mmol.g(-1).h(-1) at room temperature under light illumination (100 mW.cm(2)), which is 6 times and 17 times higher than Pd/TiO2 and bare TiO2, respectively. Moreover, the Cu-doped photocatalyst presents excellent stability without deactivation after ten cycles. Based on X-ray photoelectron spectroscopy, infrared spectroscopy and control experiments, this unexpected photocatalytic behavior mainly origins from the electron transfer effect and unique chemisorption of epoxides owing to Cu dopant.
查看更多>>摘要：Inorganic carbon (HCO3-) was efficiently converted into acetate (204.4 & PLUSMN; 0.5 mM with a coulombic efficiency of 96 & PLUSMN; 3% over 24 days operation) in a photo-assisted microbial electrosynthesis system (MES) using a urea-treated MnFe2O4/g-C3N4 cathode and the nonphotosynthetic bacteria Serratia marcescens Q1. The remarkable photocatalytic performance of MnFe2O4/g-C3N4 heterojunction was resulted from the charge transfer mechanism switch (from type II to Z-scheme) induced by the synergistic effect of oxygen vacancies and pyrrolic N after urea treatment. The increased pyrrolic N was conductive to photoinduced electron transfer while the oxygen va-cancies provided a higher fraction of surface-active sites for H-2 evolution, which was metabolized in-situ with bicarbonate by S. marcescens Q1 to yield acetate via the Wood-Ljungdahl pathway. This study provides a simple and feasible strategy for switching the photocatalytic charge transfer in a spinel-based heterojunction and offers new insights for ingeniously synthesizing photocatalysts with high CO(2 )conversion in MES.
NSTL
Elsevier