光化学法制备过渡金属-氮共掺杂多孔炭基CO2电还原催化剂

过渡金属-氮共掺杂炭材料是一类高效的CO₂电还原催化剂。以热解聚合物制备的氮掺杂炭材料为载体,浸渍镍源,经红外灯光照2 h,利用光化学法制备了高分散的镍-氮-碳催化剂（Ni/NC）。采用扫描电镜（SEM）、物理吸附、粉末X射线衍射（XRD）、X射线光电子能谱（XPS）等手段对催化剂的形貌、结构、物相和组成进行了分析,并评价了催化剂的CO₂电还原反应性能。电化学性能测试结果表明,在0.5 mol/L的KHCO₃电解液中,镍的负载量为2 %（质量分数）时催化性能最好,CO分电流密度得到有效提升,塔菲尔斜率为492 mV/dec,起始过电位为286 mV;在-0.6 V（vs.RHE）下,CO的法拉第效率为78%,在-1.0 ~-0.5 V（vs.RHE）内,n（CO）/n（H₂）=0.5~3.6。

Preparation of transition metal-nitrogen co-doped porous carbon-based CO2electro-reduction catalyst through photochemical method

Transition metal-nitrogen co-doped carbon materials are a kind of high efficiency electrocatalysts for CO₂ reduction. The nitrogen-doped carbon material prepared by pyrolysis polymer was used as the support,and the nickel precursor was synthesized by an impregnation method.The highly dispersed Ni-N-C type catalysts（Ni/NC） were obtained through the photochemical method with the assistant of infrared lamp for 2 h.The morphology,structure,phase and composition of catalysts were characterized by scanning electron microscopy（SEM）,gas physisorption,X-ray diffraction（XRD） and X-ray photoelectron spectroscopy（XPS）.The electrocatalytic activity on CO₂ reduction reaction was analyzed.The electrochemical performance test results showed that with the electrolyte（KHCO ₃） of 0.5 mol/L,the sample with Ni loading of 2% delivered the best catalytic performance and CO partial current density was significanted improved.,the Tafel slope was 492 mV/dec,and the initial overpotential was 286 mV.At -0.6 V（vs.RHE）,the Faradaic efficiency of CO was 78%.The ratio of 0.5~3.6 for n（CO）/n（H₂） was achieved in the range of -1.0~ -0.5 V（vs.RHE）.