摘要：Controllably mounting foreign atoms on the surfaces of earth-abundant electrocatalysts strongly improve their surface electronic properties for optimizing the catalytic performance of surficial sites to an unusual level,and provides a good platform to gain deep insights into catalytic *** present work describes,employing ultrafine W2C nanoislands(average size:2.3 nm)monodispersed on the N,P dual-doped carbon frameworks as a model system,how to regulate the atomic phosphorous-mounting effect on the surfaces of W_(2)C to derive an active and stable P-mounting W_(2)C(WCP)catalyst for both acidic and alkaline hydrogen evolution reaction(HER).Since in situ phosphorus substitution into carbon sites of preformed W_(2)C nanoislands gradually proceeds from surfaces to solids,so that using a proper amount of phosphorus sources can readily control the surface mounting level to avoid the mass P-doping into the *** this way,the activity per active site of WCP catalyst with robust stability can be optimized to 0.07 and 0.56 H_(2 )s^(-1) at-200 mV overpotential in acid and base,respectively,which reach up to the several-fold of pure-phase W_(2)C(0.01 and 0.05 H_(2) s^(-1)).Theoretical investigations suggest that compared with solid P doping,the P mounting on W_(2)C surface can more remarkably enhance its metallicity and decrease the hydrogen release *** finding disclosed a key correlation between surface foreign atom-mounting and catalytic activity,and suggested a logical extension to other earth-abundant catalysts for various catalytic reactions.

摘要：寻找高活性、碱性稳定且具有极低过电位的非贵金属基析氧反应(OER)催化剂有巨大的价值,但由于OER缓慢的动力学,使其商业化面临相当大的挑战.本文中,我们通过一种自适应的表面重构方法设计了一种强耦合核壳纳米结构的预催化剂.该预催化剂由内部生长的Ni_(3)N/Ni异质结构核和超薄Ni_(3)N壳(Ni_(3)N/Ni@Ni_(3)N)组成,通过逐步的热氮化路径合成.Ni_(3)N/Ni@Ni_(3)N样品在电流密度10 mA·cm^(-2)下展现出超低的过电位(229 mV),其在过电位270 mV下,电流密度为单独的Ni_(3)N、Ni以及商业RuO_(2)催化剂的17,37和20倍,同时具有较低的塔菲尔斜率(55 mV·dec^(-1)).在OER过程中,Ni_(3)N/Ni@Ni_(3)N样品的表面发生了重构,生成了高活性的NiOOH.原位拉曼光谱和非原位电子显微镜的研究证实了这一点.密度泛函理论(DFT)计算结果表明,NiOOH到Ni_(3)N的界面电子转移产生了带正电的Ni阳离子,大大降低了OER中间产物吸附/脱附的能垒.