碳掺杂MoS_(2)@Mo电极增强电解水析氢反应

高性能电极材料开发是大电流密度电解水制氢的关键.实验采用微波等离子体化学气相沉积(MPCVD)实现Mo基体直接生长活性MoS_(2)纳米片阵列,设计CH4/H2等离子体实现碳掺杂原位调控活性层MoS_(2)晶相结构,制备了呈异质结构的1T/2H-MoS_(2)@Mo电极.电化学性能测试显示,1T/2H-MoS_(2)@Mo电极在1000 mA cm^(-2)大电流密度下表现出281 mV低过电位和超100 h的持续稳定性.Butler-Volmer(B-V)拟合证实,1T/2H-MoS_(2)@Mo具有媲美Pt的动力学性能.密度泛函理论(DFT)计算表明,C掺杂诱导形成的1T/2H-MoS_(2)晶体畴壁具有非对称性结构,造成MoS_(2)表面电荷的不均匀分布,进而激活表面惰性S位点,降低氢吸附自由能(ΔGH*);同时,Mo基体与活性层1T/2H-MoS_(2)间的能带重叠效应,赋予1T/2H-MoS_(2)@Mo优异的载体/活性层界面结构稳定性.MPCVD自生长晶相结构调控策略为大电流密度非贵金属析氢电极制备提供了技术支持.

Efficient degradation of chlorobenzene in a non-thermal plasma catalytic reactor supported on CeO_2/HZSM-5 catalysts

Chlorobenzene removal was investigated in a non-thermal plasma reactor using CeO2/HZSM-5catalysts.The performance of catalysts was evaluated in terms of removal and energy efficiency.The decomposition products of chlorobenzene were analyzed.The results show that CeO2/HZSM-5 exhibited a good catalytic activity,which resulted in enhancements of chlorobenzene removal,energy efficiency,and the formation of lower amounts of by-products.With regards to CO2 selectivity,the presence of catalysts favors the oxidation of by-products,leading to a higher CO2 selectivity.With respect to ozone,which is considered as an unavoidable by-product in air plasma reactors,a noticeable decrease in its concentration was observed in the presence of catalysts.Furthermore,the stability of the catalyst was investigated by analyzing the evolution of conversion in time.The experiment results indicated that CeO2/HZSM-5 catalysts have excellent stability：chlorobenzene conversion only decreased from 78%to 60%after 75 hr,which means that the CeO2/HZSM-5 suffered a slight deactivation.Some organic compounds and chlorinated intermediates were adsorbed or deposited on the catalysts surface as shown by the results of Fourier Transform Infrared（FT-IR） spectroscopy,scanning electron microscope（SEM） and energy dispersive X-ray spectroscopy（EDS） analyses of the catalyst before and after the reaction,revealing the cause of catalyst deactivation.