The electrochemical reduction of CO to syngas with a tunable CO/H ratio is regarded as an economical and promising method for the future. Herein, a series of earth-abundant Zn catalysts with different crystal facet ratios of Zn(002) to Zn(101) in the bulk phase have been prepared on electrochemically polished Cu foam by the electrochemical deposition method. The Zn catalyst with more (101) crystal facets show good electrochemical activity for the CO reduction reaction (CORR) to CO and that with more (002) crystal facets favor the hydrogen evolution reaction. The linear relationship between the crystal facet ratio of Zn(101) to Zn(002) and the Faradaic efficiency (FE) of CORR to CO has been revealed for the first time. The prepared catalyst with more (101) facets show greater than 85% FE to syngas at -0.9 V (vs reversible hydrogen electrode) in aqueous electrolyte, with tunable CO/H ratios ranging from 0.2 to 2.31 that can be used in existing industrial systems. Meanwhile, the mechanism of electroreduction of CO on the Zn electrode has been studied by in situ infrared absorption spectroscopy. The highly selective role of the Zn(101) crystal facet in the CORR to CO has been evidenced by density functional theory calculations.

This study employed a novel modification strategy to overcome the intrinsic poor rate performance, large initial irreversible capacity, and low cycling stability of Li-rich layered oxide (LLO) cathode materials. The strategy involved simultaneous in situ spinel Li1+x Ni y Mn2–y O4 coating using Mn-TFBDC (TFBDC: 2,3,5,6-tetrafluoro-1,4-benzenedicarboxylic acid) as the precursor and organic fluorine doping agent. Uniform Li1+x Ni y Mn2–y O4 coating of the LLO surface was easily achieved via the coordination of the carboxylic acid ligands with the manganese ions and subsequent heat treatment. TFBDC-assisted treatment rendered significantly enhanced electrochemical performance to LLO. The first discharge specific capacity of LLO modified by TFBDC-assisted treatment (TA-LLO) was enhanced to 302.1 mAh g–1, and the capacity retention significantly increased from 80.8 to 98.9% after 100 cycles at 1C, compared with that of the pristine LLO (PLLO). Electrochemical impedance spectroscopy and the galvanostatic intermittent titration technique confirmed that TA-LLO had a lower charge transfer resistance and higher ion diffusion coefficient than PLLO. These results suggest that the use of organic fluorine is an effective strategy to carry out fluorine doping simultaneously with spinel Li1+x Ni y Mn2–y O4 coating for fast Li+ ion diffusion and significantly improved electrochemical properties of LLOs.

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Selective hydrogenation of biomass 5-Hydroxymethylfurfural (HMF) to 2, 5-dimethylfuran (DMF) which is a suitable candidate for liquid fuel has been widely concerned. Developing efficient and economic catalysts for the hydrogenation of HMF to DMF under mild conditions is a crucial issue. Here series monometallic Cu-based catalysts were synthesized from controlled thermolysis of Cu-BTC metal-organic frameworks and characterized by TG, N 2 adsorption-desorption, XRD, XPS, SEM, TEM, and H 2 -TPR techniques. The CuO x @C catalyst with Cu 2 O/Cu composites enwrapped in porous carbon matrix derived from Cu-BTC by two steps thermolysis treatment shows high hydrogenation activity with 100% conversion of HMF and 92% selectivity of DMF at 180°C under 3 MPa H 2 pressure. The oxidation treatment following up the thermolysis of Cu-BTC under inert atmosphere increases the content of Cu + in the catalyst and improves the activity of the catalyst, which is mainly owe to the synergetic effect between Cu + and Cu 0 .