The formation of (bi)carbonates is a pressing issue for CO2 electroreduction in neutral or alkaline solutions. It adversely causes low single-pass conversion efficiency as a result of (bi)carbonate crossover, as well as limited device lifetimes as a result of (bi)carbonate precipitation at the cathode. One emerging solution to circumvent this challenge is conducting the reaction in acids. To this end, we here demonstrate an acid-fed membrane electrode assembly (MEA) for CO2 electroreduction to CO. A diluted electrolyte with an H+ to Cs+ ratio of 1:1 and a relatively low current density are optimal conditions to achieve high CO Faradaic efficiencies. A relatively high H+ versus Cs+ ratio offers high electrocatalytic activities. By systematically evaluating the impact of H+ and Cs+ concentration on the electrochemical performance, we uncover the essential role of the balance between the rates of (bi)carbonate formation and H+ diffusion in determining the selectivity and activity. As a result, we report a CO partial current density of ∼105 mA cm–2 at an ∼4 V cell voltage, a near-doubled activity toward CO compared to a neutral MEA at a similar voltage. Under the optimal conditions for long-term operation, our acid-fed membrane electrode assembly is capable of delivering a CO Faradaic efficiency of ∼80%, an extraordinary single-pass conversion efficiency of ∼90% (about twice that of neutral MEA), and a 50 h long-term stability notably superior to those in previous reports.

Graphitic carbon nitride (g-C3N4), with a unique structure analogous to graphite, has attracted ever-increasing attention for electrochemical energy storage due to its high surface area, metal-free characteristic, low cost and facile synthesis.

Compared to traditional metal oxides, metal-organic frameworks exhibit excellent properties, such as a high surface area, significant thermal stability, low density, and excellent electrochemical performance. Here, a simple process is proposed for the fabrication of rod-like vanadium metal-organic frameworks (V (O)(bdc), bdc = 1,4-benzenedicarboxylate, or MIL-47), and the effect of the structure on the electrochemical performance is investigated via a series of electrochemical measurements. The V (O)(bdc) electrode exhibits a maximum specific capacitance of 572.1 F g at current densities of 0.5 A g . More significantly, aqueous and solid-state asymmetric supercapacitors are successfully assembled. The solid-state device shows an excellent energy density of 6.72 mWh cm at a power density of 70.35 mW cm . This superior performance confirms that V (O)(bdc) electrodes are promising materials for applications in supercapacitors.

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Chemocatalytic lignin valorization strategies are critical for a sustainable bioeconomy, as lignin, especially technical lignin, is one of the most available and underutilized aromatic feedstocks. Here, we provide the first report of an intensified reactive distillation–reductive catalytic deconstruction (RD-RCD) process to concurrently deconstruct technical lignins from diverse sources and purify the aromatic products at ambient pressure. We demonstrate the utility of RD-RCD bio-oils in high-performance additive manufacturing via stereolithography 3D printing and highlight its economic advantages over a conventional reductive catalytic fractionation/RCD process. As an example, our RD-RCD reduces the cost of producing a biobased pressure-sensitive adhesive from softwood Kraft lignin by up to 60% in comparison to the high-pressure RCD approach. Last, a facile screening method was developed to predict deconstruction yields using easy-to-obtain thermal decomposition data. This work presents an integrated lignin valorization approach for upgrading existing lignin streams toward the realization of economically viable biorefineries.

Currently, the application of new energy conversion and storage technologies is urgent in order to meet the increasing requirements for energy.

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The electrochemical carbon dioxide (CO2) reduction provides a means to upgrade CO2 into value‐added chemicals. When powered by renewable electricity, CO2 electroreduction holds the promise of chemical manufacturing with carbon neutrality. A commercially relevant CO2 electroreduction process should be highly selective and productive toward desired products, energetically efficient for power conversion, and stable for long‐term operation. To achieve these goals, designing gas‐diffusion catalytic electrodes and prototyping reactors built upon in‐depth understandings of the reaction mechanisms are of paramount importance. In this review, the fundamentals of gas‐diffusion electrodes are briefly presented. Then, the most recent advances in developing high‐performance CO2 reduction using gas‐diffusion electrodes are overviewed. Reactor engineering aiming at enhancing productivity, energy efficiency, CO2 single‐pass utilization, and operating lifetime is further discussed. Challenges in developing CO2 electroreduction systems are included. The prospects for advancing CO2 electroreduction toward practical applications are also narrated.