Towards Efficient MXene-based Electrocatalysts for Electrochemical CO2 Reduction

Robertshaw, Samuel and Toghill, Kathryn (2025) Towards Efficient MXene-based Electrocatalysts for Electrochemical CO2 Reduction. PhD thesis, Lancaster University.

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Abstract

The increased utilisation of non-renewable energy sources in recent decades has had a drastic impact on the Earth’s climate. With significant anthropogenic carbon dioxide (CO2) emissions causing drastic changes to the Earth’s atmosphere, the decarbonisation of energy generation alongside renewable energy alternatives to fossil fuels is crucial. The electrocatalytic reduction of CO2 (eCO2RR) to value-added chemicals is an attractive and sustainable technology towards achieving a low- carbon economy. However, current electrocatalysts have been reported to suffer from low selectivity, poor stability, and high overpotentials, thus limiting their scale- up potential. There is a critical demand for the development of efficient novel electrocatalysts with high selectivity towards desired products. A new class of 2- dimensional materials known as MXenes has gained significant interest in the recent literature due to their unique structural and electronic properties. Several computational studies have highlighted Ti3C2Tx to be of significant interest as an eCO2RR electrocatalyst. This thesis works towards evaluating Ti3C2Tx for the application of eCO2RR catalysis, with a particular focus on the fabrication of MXene- modified electrodes using MXene powders. Additionally, the treatment and handling of Ti3C2Tx powders is reported herein, with the successful -O and -OH surface functionalisation of a commercial MXene also demonstrated via ozone modifications. Finally, the design and manufacture of bespoke electrochemical cells is reported, with the aim of accommodating a wealth of electrode morphologies while simultaneously optimising and improving current systems for accurate eCO2RR product quantification.