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We demonstrate pOH imaging with confocal microscopy to probe the microenvironment of an operating CO2 reduction gas diffusion electrode. We find that the micrometer-scale morphology plays an important role in defining the CO2 reduction performance.

AbstractGrowing concern with the effects of CO2 emissions due to the combustion of petroleum‐based transportation fuels has motivated the search for means to increase engine efficiency. The discovery of ethers with low viscosity presents an important opportunity to improve engine efficiency and fuel economy. We show here a strategy for the catalytic synthesis of such ethers by reductive etherification/O‐alkylation of alcohols using building blocks that can be sourced from biomass. We find that long‐chain branched ethers have several properties that make them superior lubricants to the mineral oil and synthetic base oils used today. These ethers provide a class of potentially renewable alternatives to conventional lubricants produced from petroleum and may contribute to the reduction of greenhouse gases associated with vehicle emissions.

AbstractInvited for this month′s cover is the group of Alexis T. Bell at The University of California, Berkeley in Berkeley, California. The image shows the utility of gold nanoparticles deposited on hydrotalcite (Au/HT) for the continuous gas‐phase non‐ oxidative dehydrogenation reaction of bioderived C2–C4 alcohols to the respective carbonyl compounds and hydrogen. The Communication itself is available at 10.1002/cssc.201500786.

The design for a novel artificial photosynthetic system is proposed that can be ten-fold more efficient than natural photosynthesis and produce almost pure liquid fuel.

We report a new Ce-rich family of active oxygen evolution reaction (OER) catalysts composed of earth abundant elements, discovered using high-throughput methods.

Electrochemical carbon dioxide reduction (CO2R) provides a promising pathway for sustainable generation of fuels and chemicals. Copper (Cu) electrocatalysts catalyse CO2R to valuable multicarbon (C2+) products, but their selectivity depends on the local microenvironment near the catalyst surface. Here we systematically explore and optimize this microenvironment using bilayer cation- and anion-conducting ionomer coatings to control the local pH (via Donnan exclusion) and CO2/H2O ratio (via ionomer properties), respectively. When this tailored microenvironment is coupled with pulsed electrolysis, further enhancements in the local ratio of CO2/H2O and pH are achieved, leading to selective C2+ production, which increases by 250% (with 90% Faradaic efficiency and only 4% H2) compared with static electrolysis over bare Cu. These results underscore the importance of tailoring the catalyst microenvironment as a means of improving overall performance in electrochemical syntheses. Copper catalyses electrochemical reduction of CO2 to valuable multicarbon products, but its selectivity depends on the local microenvironment near the catalyst surface. Here, the authors explore and optimize this environment to improve performance using bilayer ionomer coatings to control the local pH and CO2/H2O ratio.

Abstract1,3‐Butadiene (1,3‐BD) is a high‐value chemical intermediate used mainly as a monomer for the production of synthetic rubbers. The ability to source 1,3‐BD from biomass is of considerable current interest because it offers the potential to reduce the life‐cycle greenhouse gas (GHG) impact associated with 1,3‐BD production from petroleum‐derived naphtha. Herein, we report the development and investigation of a new catalyst and process for the one‐step conversion of ethanol to 1,3‐BD. The catalyst is prepared by the incipient impregnation of magnesium oxide onto a silica support followed by the deposition of Au nanoparticles by deposition–precipitation. The resulting Au/MgO‐SiO2 catalyst exhibits a high activity and selectivity to 1,3‐BD and low selectivities to diethyl ether, ethylene, and butenes. Detailed characterization of the catalyst shows that the desirable activity and selectivity of Au/MgO‐SiO2 are a consequence of a critical balance between the acidic–basic sites associated with a magnesium silicate hydrate phase and the redox properties of the Au nanoparticles. A process for the conversion of ethanol to 1,3‐BD, which uses our catalyst, is proposed and analyzed to determine the life‐cycle GHG impact of the production of this product from biomass‐derived ethanol. We show that 1,3‐BD produced by our process can reduce GHG emissions by as much as 155 % relative to the conventional petroleum‐based production of 1,3‐BD.

Density functional theory was used to investigate the mechanism and kinetics of methanol oxidation to formaldehyde over vanadia supported on silica, titania, and zirconia. The catalytically active site was modeled as an isolated VO4 unit attached to the support. The calculated geometry and vibrational frequencies of the active site are in good agreement with experimental measurements both for model compounds and oxide-supported vanadia. Methanol adsorption is found to occur preferentially with the rupture of a V−O-M bond (M = Si, Ti, Zr) and with preferential attachment of a methoxy group to V. The vibrational frequencies of the methoxy group are in good agreement with those observed experimentally as are the calculated isobars. The formation of formaldehyde is assumed to occur via the transfer of an H atom of a methoxy group to the O atom of the VO group. The activation energy for this process is found to be in the range of 199−214 kJ/mol, and apparent activation energies for the overall oxidation of met...