The morphologies of sodium electrodeposits and gas evolution were studied in a system comprising a symmetrical Na/Na optical cell, a digital microscope, and an electrochemical workstation. Sodium deposition in ethylene carbonate (EC), diethyl carbonate (DEC), and propylene carbonate (PC) generated large volumes of gas and fragile, porous dendrites. The use of fluoroethylene carbonate (FEC) greatly reduced gassing during deposition and demonstrated superior cycling performance, impedance, and cycling efficiency when it was used as a cosolvent with DEC (1:1 vol); however, porous depositions persisted. Time of flight secondary-ion mass spectrometry revealed that the solid-electrolyte interphase formed in FEC/DEC, in contrast with the EC/DEC electrolyte, is thicker, richer in NaF, and forms a less dense polymer organic layer.

Adding 10 mM KPF6 to the 1 M LiPF6 in ethylene carbonate/dimethyl carbonate electrolyte of symmetrical Li | Li cells eliminated the growth of dendrites at 0.5 mA cm–2 current density and massively reduced, but did not eliminate, the growth of dendrites at 2.5 mA cm–2. The added KPF6 increased the fraction of inorganic salts in the solid electrolyte interface, making it thinner and more Li+ conductive. It overcame the growth of dendrites resulting from inadequate nucleation density but not dendrite growth into the depletion layer, which scales with the layer’s thickness, i.e., the current density.

Controlling selectivity is a key goal in the design of a heterogeneous catalyst. Herein, we present detailed characterization and activity of silica‐supported cobalt catalysts modified by atomic layer deposition of ZnO. After reduction, the resulting catalysts exhibit substantial selectivity towards alcohol production during CO hydrogenation compared to catalysts containing only cobalt. The prepared catalysts have up to 46 % selectivity toward alcohols with 39 % of the alcohols corresponding to ethanol and other higher alcohols, albeit with reduced activity. In situ characterization of the catalyst by X‐ray diffraction and X‐ray absorption spectroscopy reveals details on the structural evolution in syngas, CO+H2, and shows that ZnO promotion of Co results in the formation of Co2C under catalytic conditions. A mechanism is proposed, supported by density functional theory calculations, which explains Co2C formation by the blocking of Co step sites by Zn species. The ZnO acts a dual promoter both by facilitating Co2C formation and by modifying the resulting Co2C. The Co2C formed from the ZnO‐promoted Co catalysts displays improved thermal stability and selectivity compared with similar Co2C catalysts without Zn.

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Understanding the differences between reactions driven by elevated temperature or electric potential remains challenging,largely due to materials incompatibilities between thermal catalytic and electrocatalytic environments.W es how that Ni, N-doped carbon (NiPACN), an electrocatalyst for the reduction of CO 2 to CO (CO 2 R), can also selectively catalyze thermal CO 2 to CO via the reverse water gas shift (RWGS) representing ad irect analogy between catalytic phenomena across the two reaction environments.A dvanced characterization techniques reveal that NiPACNlikely facilitates RWGS on dispersed Ni sites in agreement with CO 2 Ra ctive site studies.F inally,w ec onstruct ag eneralized reaction drivingforce that includes temperature and potential and suggest that NiPACNc ould facilitate faster kinetics in CO 2 Rr elative to RWGS due to lower intrinsic barriers.T his report motivates further studies that quantitatively link catalytic phenomena across disparate reaction environments.