Many electrocatalysts can efficiently convert CO2 to CO. However, the further conversion of CO to higher-value products was hindered by the low activity of the CO reduction reaction and the consequent lack of mechanistic insights for designing better catalysts. A flow-type reactor could potentially improve the reaction rate of CO reduction. However, the currently available configurations would pose great challenges in reaction mechanism understanding due to their complex nature and/or lack of precise potential control. Here we report, in a standard electrochemical cell with a three-electrode setup, a supported bulk polycrystalline copper powder electrode reduces CO to hydrocarbons and multicarbon oxygenates with dramatically increased activities of more than 100 mA cm–2 and selectivities of more than 80%. The high activity and selectivity that was achieved demonstrates the practical feasibility of electrochemical CO or CO2 (with a tandem strategy) conversion and enables the experimental exploration of the CO reduction mechanism to further reduced products.

The growing threat of global climate change has received increasing attention in recent years. The conversion of CO2 to fuels and chemicals is vital for reducing emissions of greenhouse gases and neutralizing the negative impacts of CO2 emissions on the environment. Various CO2 conversion routes have been proposed on the basis of heterogeneous catalysis. However, the development of a high-performance catalyst with satisfactory activity and selectivity remains challenging. In past decades, the role of ceria in activating CO2 under mild conditions has been widely demonstrated, which has inspired the design of novel heterogeneous catalysts and contributed to the extensive catalytic applications in CO2 conversion reactions. The applications of ceria have been studied in three groups of CO2 conversion reactions, including hydrogenation of CO2, activation of CO2 with alkanes, and nonreductive CO2 transformations. Investigations into these reactions show that CeO2 is a highly tunable material with great potential for CO2 catalysis due to its unique properties such as abundant oxygen vacancy and metal–support interaction. The catalytic performance of CeO2-based catalysts can be improved by various strategies including metal doping, forming mixed oxides or solid solution, as well as morphological control. Future works are proposed to address the challenges in current research and to further advance the CeO2-based catalysts in CO2 conversion reactions.

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Electrochemical CO2 reduction reaction (CO2RR) with renewable electricity is a potentially sustainable method to reduce CO2 emissions. Palladium supported on cost‐effective transition‐metal carbides (TMCs) are studied to reduce the Pd usage and tune the activity and selectivity of the CO2RR to produce synthesis gas, using a combined approach of studying thin films and practical powder catalysts, in situ characterization, and density functional theory (DFT) calculations. Notably, Pd/TaC exhibits higher CO2RR activity, stability and CO Faradaic efficiency than those of commercial Pd/C while significantly reducing the Pd loading. In situ measurements confirm the transformation of Pd into hydride (PdH) under the CO2RR environment. DFT calculations reveal that the TMC substrates modify the binding energies of key intermediates on supported PdH. This work suggests the prospect of using TMCs as low‐cost and stable substrates to support and modify Pd for enhanced CO2RR activity.

We report on a highly compact, one diode-one resistor (1D-1R) nanopillar device architecture for SiOx-based ReRAM fabricated using nanosphere lithography (NSL). The intrinsic SiOx-based resistive switching element and Si diode are self-aligned on an epitaxial silicon wafer using NSL and a deep-Si-etch process without conventional photolithography. AC-pulse response in 50 ns regime, multibit operation, and good reliability are demonstrated. The NSL process provides a fast and economical approach to large-scale patterning of high-density 1D-1R ReRAM with good potential for use in future applications.