Taming interfacial electronic effects on Pt nanoparticles modulated by their concomitants has emerged as an intriguing approach to optimize Pt catalytic performance. Here, we report Pt nanoparticles assembled on vacancy-abundant hexagonal boron nitride nanosheets and their use as a model catalyst to embrace an interfacial electronic effect on Pt induced by the nanosheets with N-vacancies and B-vacancies for superior CO oxidation catalysis. Experimental results indicate that strong interaction exists between Pt and the vacancies. Bader charge analysis shows that with Pt on B-vacancies, the nanosheets serve as a Lewis acid to accept electrons from Pt, and on the contrary, when Pt sits on N-vacancies, the nanosheets act as a Lewis base for donating electrons to Pt. The overall-electronic effect demonstrates an electron-rich feature of Pt after assembling on hexagonal boron nitride nanosheets. Such an interfacial electronic effect makes Pt favour the adsorption of O2, alleviating CO poisoning and promoting the catalysis.

We used periodic DFT calculations to investigate the effect of alkali promoter on the selectivity of the water‐gas shift reaction (WGSR) explicitly on the Ni(1 1 1) surface. On clean Ni(1 1 1), the WGSR redox and carboxyl pathways are both kinetically competitive. The selectivity of the WGSR can be affected by methanation on Ni, in which the C−O bond cleavage pathway of CHO is the most competitive. A Ni(1 1 1) surface modified with K adatoms was used to further understand the promoter effects on the WGSR selectivity. A combined energetic and kinetic analysis from DFT calculations indicates that the K adatom stabilizes certain reactive intermediates (e.g., H2O, CO) thermodynamically but is energetically neutral or even repulsive toward other intermediates. As a result, WGSR pathways benefit from the presence of K adatoms compared to the competing methanation pathway. This study thus confirmed the promoting effects of alkali metals on the WGSR with DFT‐based mechanistic insights.

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Conventional electrolytes made by mixing simple Mg 2+ salts and aprotic solvents, analogous to those in Li-ion batteries, are incompatible with Mg anodes because Mg metal readily reacts with such electrolytes, producing a passivation layer which blocks Mg 2+ transport.Here, we report that, through tuning a conventional electrolyte-Mg(TFSI) 2 (TFSIis N(SO 2 CF 3 ) 2 -) with an Mg(BH 4 ) 2 additive, highly reversible Mg plating/stripping with a high coulombic efficiency is achieved, by neutralizing the first solvation shell of Mg cationic clusters between Mg 2+ and TFSIand enhanced reductive stability of free TFSI -. A critical adsorption step between Mg 0 atoms and active Mg cation clusters involving BH 4 anions is identified to be the key enabler for reversible Mg plating/stripping through analysis of distribution of relaxation times (DRT) from operando electrochemical impedance spectroscopy (EIS), operando electrochemical X-ray absorption spectroscopy (XAS), nuclear magnetic resonance (NMR), and density functional theory (DFT) calculations. This study suggests a new approach for developing advanced electrolytes for Mg batteries and provides a set of in-operando analysis tools for probing electrified Mg/electrolyte interfaces.