Sustainable future energy scenarios require significant efficiency improvements in both electricity generation and storage. High-temperature solid oxide cells, and in particular carbon dioxide electrolysers, afford chemical storage of available electricity that can both stabilize and extend the utilization of renewables. Here we present a double doping strategy to facilitate CO2 reduction at perovskite titanate cathode surfaces, promoting adsorption/activation by making use of redox active dopants such as Mn linked to oxygen vacancies and dopants such as Ni that afford metal nanoparticle exsolution. Combined experimental characterization and first-principle calculations reveal that the adsorbed and activated CO2 adopts an intermediate chemical state between a carbon dioxide molecule and a carbonate ion. The dual doping strategy provides optimal performance with no degradation being observed after 100 h of high-temperature operation and 10 redox cycles, suggesting a reliable cathode material for CO2 electrolysis.

The conversion of ethane, a main component of natural gas, to ethylene feed stock has attracted widespread attention since the worldwide shale gas revolution. Thermal catalysis of ethane to ethylene, mainly oxidative dehydrogenation, faces the fundamental challenge of low conversion, low selectivity, and catalyst coking. This work demonstrates an efficient conversion of ethane to ethylene in a nonoxidative dehydrogenation process in a proton-conducting solid oxide electrolyzer at ambient pressure and 700 °C. We show the highest ethane conversion of 75.2% and ∼100% ethylene selectivity even only at 0.8 V in this electrochemical catalysis process. The electrochemical pumping of protons at anode with active exsolved metal–oxide interfaces enhances anode activity, while the metal–oxide interface interactions further engineer the ethane conversion in the electrochemical dehydrogenation process. We exsolve metal–oxide interface architecture at nanoscale on the electrode scaffold to improve coking resistance and catalyst stability. We further present the reduction of carbon dioxide to carbon monoxide in the cathode combined with ethane conversion in the anode, and we show the higher performance of ethane conversion in the anode with syngas production in the cathode. The electrochemical dehydrogenation process would provide an alternative method for the petrochemical production and a thermochemical practice in a clean energy mode.

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Oxidative dehydrogenation of ethane to ethylene is an important process in light olefin industry; however, the over‐oxidation of ethane leads to low ethylene selectivity. Here, we report a novel approach to electrochemical oxidative dehydrogenation of ethane in anode in conjunction with CO2 reduction at cathode in a solid oxide electrolyser using a porous single‐crystalline CeO2 electrode at 600 °C. We identify and engineer the flux and chemical states of active oxygen species that evolve from the lattice at anode surface to activate and dehydrogenate ethane to ethylene via the reaction of epoxy species. Active oxygen species (O2−, O22− and O2−) at the anode surface effectively dehydrogenate ethane to ethylene, but O− species tend to induce deep oxidation. We demonstrate exceptionally high ethylene selectivity of 95 % and an ethane conversion of 10 % with a durable operation of 300 h.

A facile one-pot method was used to synthesize Pt/Cu 2 O/GNs and Pd/Cu 2 O/GNs composites. Pt or Pd nanoparticles are deposited onto graphene sheets (GNs) and Cu 2 O via synchronous reduction of K 2 PtCl 4 (K 2 PdCl 4 ), Cu(OH) 2 and graphene oxide (GO) with glucose as a reducing agent under microwave irradiation. The formation of Cu 2 O promotes the nucleation of Pt(0) or Pd(0) particles and favors more complete reduction of PtCl 4 2À or PdCl 4 2À . Catalytic properties of as-prepared composites for methanol oxidation reaction (MOR) were evaluated by cyclic voltammetry (CV), chronoamperometry, CO ads stripping voltammetry and electrochemical impedance spectrum (EIS). Electrochemical experiments showed that Pt/Cu 2 O/GNs and Pd/Cu 2 O/GNs had much higher catalytic activity and stability for MOR and better resistance to CO poisoning compared with the commercially available Johnson Matthey 20% Pt/C catalyst (Pt/C-JM) and Sigma-Aldrich 20% Pd/C catalyst (Pd/C-SA). Especially under the UV irradiation, the total peak current density and catalytic stability of Pt/Cu 2 O/GNs and Pd/Cu 2 O/GNs drastically increase, which may result from the synergistic effect between the electro-catalytic and photo-catalytic properties. In brief, the cooperation among Pt (Pd), Cu 2 O and GNs promotes remarkably the catalytic performance for MOR on Pt/Cu 2 O/GNs and Pd/Cu 2 O/GNs either without light or with UV irradiation.

The solid oxide CO electrolyzer has the potential to provide storage solutions for intermittent renewable energy sources as well as to reduce greenhouse gas emissions. One of the key challenges remains the poor adsorption and activity toward CO reduction on the electrolyzer cathode at typical operating conditions. Here, we show a novel approach in tailoring a perovskite titanate (La, Sr)TiO cathode surface, by the in situ growing of SrO nanoislands from the host material through the control of perovskite nonstoichiometry. These nanoislands provide very enhanced CO adsorption and activation, with stability up to 800 °C, which is shown to be in an intermediate form between carbonate ions and molecular CO. The activation of adsorbed CO molecules results from the interaction of exsolved SrO nanoislands and the defected titanate surface as revealed by DFT calculations. These cathode surface modifications result in an exceptionally high direct CO electrolysis performance with current efficiencies near 100%.

Remarkable cathode performances for CO2 electrolysis have been achieved by introducing more oxygen vacancies in Mn/Cr-doped and A-site deficient titanates.

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