Utilization of CO<sub>2</sub> for Electrocarboxylation of Benzophenone Using MXene-Based Electrodes: A Sustainable Approach
Sariga, Aathilingam Vijayaprabhakaran, Murugavel Kathiresan, V. Suryanarayanan, Anitha Varghese
Abstract
The significant rise in atmospheric carbon dioxide (CO 2 ) levels has prompted the need to develop efficient methods for CO 2 conversion and fixation methods. Electrocarboxylation reaction is a highly efficient and sustainable method for activating and utilizing CO 2, yielding essential carboxylic acids and their analogues, which are important intermediates in the pharmaceutical and fuel industries. This research demonstrates the efficiency of 2D Ti 3 C 2 T x and Ta 2 CT x MXene-modified carbon fiber paper electrodes (Ti 3 C 2 T x /CFP and Ta 2 CT x /CFP) for CO 2 fixation with benzophenone in a tetrabutylammonium bromide/acetonitrile (TBABr/CH 3 CN) medium, yielding benzilic acid. Ti 3 C 2 T x /CFP exhibited superior electrocatalytic activity with a lower reduction potential for benzophenone at −1.0 V and achieved a 72% yield of benzilic acid at an optimum current density of 50 mA cm –2 . In comparison, Ta 2 CT x /CFP exhibited a cathodic peak at −1.08 V, producing a 66% yield at 70 mA cm –2 . The electron paramagnetic resonance spectrum substantiates the generation of reactive radical intermediates during the reaction. Ti 3 C 2 T x /CFP showed robust structural stability with ∼88% Faradaic efficiency and a turnover frequency of 1.90444 × 10 –5 s –1, indicating its potential for CO 2 fixation.