Efficient Electrochemical Reduction of Carbon Monoxide to High Concentrated Multi-carbon (C2+) Alcohol

Description

The CO2electroreduction reaction (CO2RR) powered by renewables offers a sustainable approach to store intermittent renewable energy and convert CO2into valuable chemicals and fuels, thereby reducing the dependence on fossil fuels, as well as contributing to the target of achieving carbon neutrality before 2050 set by Hong Kong. Current CO2RR studies have been predominantly conducted in alkaline or neutral media, leading to severe CO2loss due to the carbonate/bicarbonate formation and thus the energy penalty for CO2regeneration. The carbon monoxide electroreduction reaction (CORR) following CO2reduction to CO – a two-step cascade CO2RR process – is a promising solution to address the CO2loss issue in direct CO2RR. The main C2+alcohols – ethanol and n-propanol – are particularly desirable in CORR due to their high market price and growing demand. While exciting advances in CORR to ethanol and n-propanol are achieved, the low alcohol concentration issue in current CO-to-C2+alcohol systems leads to high energy penalty for recovering alcohol products. In this project, based on our prior research experience in CO2RR/CORR-related catalyst design and reaction engineering, we aim to address the challenge of producing high concentrated C2+alcohols in CORR through the integration of system development and catalyst design. First, we will develop a bipolar membrane (BPM) based membrane electrode assembly (MEA) system to decrease the crossover of generated C2+alcohols from cathode to anode during CORR.Our preliminary resultsdemonstrate, compared to other CO-to-C2+alcohol electrocatalysis systems, the BPM-based MEA system much decreases the crossover of C2+alcohols. Second, based on the reaction environment in the BPM-based MEA system, we will design high-efficiency CO-to-ethanol/n-propanol catalysts. Third, uniting the high-efficiency CO-to-ethanol/n-propanol catalysts and the BPM-based MEA system, we will optimize the reaction conditions to achieve high concentrated C2+alcohols in CORR. Finally, we will employ in situ Raman and operando XAS to investigate the CORR reaction process, which enables us to explore the possible reaction mechanisms of CO-to-C2+alcohols and active sites of catalysts. This project will give guidance for the further design of high-efficiency CO-to-C2+alcohol catalysts and provide a new technology to produce concentrated C2+alcohol products in CORR, which can contribute to future potential practical application of CO-to-C2+alcohol electrocatalysis technologies.