Electrochemical Reduction of CO ₂ to CH ₄ under Ultrasonic Irradiation Using an Electroplated Pt Catalyst

High Resolution Image Download MS PowerPoint Slide Electrochemical CO 2 reduction to produce CH 4 represents an attractive approach for achieving a sustainable society. Although Pt electrocatalysts can reduce CO 2 to adsorbed CO (CO ads, a key intermediate in CO 2 reduction) at low overpotentials in aqueous solutions, CO ads binds strongly to the Pt surface and is not further reduced to CH 4 . In this study, the CO 2 electroreduction reaction was investigated using an electroplated Pt catalyst in combination with ultrasonic irradiation to achieve the conversion of CO ads to CH 4 . The electroplated Pt catalyst exhibited a nanosized jagged structure with an electrochemical surface area ∼10 times larger than its geometrical surface area. Significantly, the electrochemical reduction of CO 2 performed under 28 kHz ultrasonic irradiation on the electroplated Pt catalyst in 0.5 mol dm –3 H 2 SO 4 at 0.12 V vs. RHE (reversible hydrogen electrode) enabled the elimination of CO ads . Under these conditions, CH 4 formation proceeded via the Langmuir–Hinshelwood mechanism involving CO ads and adsorbed H, achieving a Faradaic efficiency of 69.7% at an overpotential of only 0.05 V with external ultrasound energy. These findings will provide useful insights for the design of carbon capture, utilization, and storage strategies as significant technologies for the electrochemical reduction of CO 2 to produce CH 4 .