Hydrogen/deuterium (H/D) substitution at electrochemical interfaces can provide insights into fundamental electrochemical processes. Periodic nuclear–electronic orbital density functional theory (NEO-DFT), which treats specified nuclei quantum mechanically on the same level as the electrons, enables such H/D isotope effects to be investigated computationally. Herein, periodic NEO-DFT is applied to OH–/OD– adsorption, H/D adsorption, and H2O/D2O monolayers at a Pt(111) surface. These calculations inherently include anharmonic zero-point energy and nuclear delocalization of hydrogen and deuterium. Thus, they capture structural differences between H/D isotopologues, guide interpretation of experimental cyclic voltammograms, identify favored adsorption sites, and characterize differences in H2O/D2O hydrogen-bonding interactions. Periodic NEO-DFT maintains the favorable computational scaling of conventional DFT, predicts geometric isotope effects, and can be combined with techniques to model an applied potential. Thus, periodic NEO-DFT represents a promising tool for probing the structures of electrochemical interfaces, interpreting experimental isotope studies, and elucidating electrocatalytic mechanisms.

Dehalogenation is a critical transformation in chemical synthesis but remains limited by catalyst deactivation and low selectivity in industrial processes. Here, we report an alternating current (AC) ...

Tafel slope analysis, first proposed by Julius Tafel in 1905 and supported by the Butler–Volmer equation, is widely used to elucidate electrocatalytic mechanisms and evaluate kinetics. However, some misuses still frequently occur in the literature, calling for rigorous mechanistic investigations at single-crystal electrodes and under well defined mass-transport conditions.

Modifying electrocatalysts with ionic liquids (ILs) not only allows for precise control of selectivity but also often directly impacts the stability of the electrocatalyst. In this work, we study how ...

Operando/in situ methods have revolutionized our fundamental understanding of molecular and structural changes at solid–liquid interfaces and enabled the vision of “watching chemistry in action”. Operando transmission electron microscopy (TEM) emerges as a powerful tool to interrogate time-resolved nanoscale dynamics, which involve local electrical fields and charge transfer kinetics distinctly different from those of their bulk counterparts. Despite early reports on electrochemical or heating liquid-cell TEM, developing operando TEM with simultaneous electrochemical and thermal control remains a formidable challenge. Here, we developed operando heating and cooling electrochemical liquid-cell scanning TEM (EC-STEM). By integrating a three-electrode electrochemical circuit and an additional two-electrode thermal circuit, we can investigate heterogeneous electrochemical kinetics across a wide temperature range of −50 to 300 °C. We used Cu electrodeposition/stripping processes as a model system to demonstrate quantitative electrochemistry from −40 to 95 °C in both transient and steady states in aqueous and organic solutions, which paves the way for investigating energy materials operating in extreme climates. Machine learning-assisted quantitative 4D-STEM structural analysis in cold liquids (−40 °C) reveals a distinct two-stage growth of nanometer-scale mossy Cu nanoislands with random orientations followed by μm-scale Cu dendrites with preferential orientations. This work benchmarked electrochemistry in the three-electrode EC-STEM and systematically investigated the temperature and pH dependence of the Pt pseudoreference electrode (RE). At room temperature, the Pt pseudo-RE shows a reliable potential of 0.8 ± 0.1 V vs the standard hydrogen electrode and remains pH-independent on the reversible hydrogen electrode scale. We anticipate that operando heating/cooling EC-STEM will become invaluable for understanding fundamental temperature-controlled nanoscale electrochemistry and advancing renewable energy technologies (e.g., catalysts and batteries) in realistic climates.

CO2 reduction reaction (CO2RR) facilitates the sustainable synthesis of fuels and chemicals. Although copper (Cu) enables CO2-to-multicarbon product (C2+) conversion, Cu-based electrocatalysts, partic...

Optimizing electrocatalyst performance requires insights into surface and subsurface structures under reaction conditions. This study uncovers hydrogen-induced reconstruction processes on low-index p....