Electrocatalytic Reduction of CO<sub>2</sub> to Long-Chain Hydrocarbons on (FeCoNiCu)<sub>3</sub>O<sub>4</sub> Medium Entropy Oxide Nanoparticles
Ahmad Ostovari Moghaddam, Seyedsaeed Mehrabi-Kalajahi, Mohammad Moaddeli, Amin Abdollahzadeh, Seyed Amir Hossein Vasigh, Segun Ahemba Akaahimbe, Mahya Nangir, Rahele Fereidonnejad, Behrouz Shaabani, Mariappan Anandkumar, Sergey Aksenov, Andrey S. Vasenko, Andreu Cabot
Abstract
Electrocatalytic CO 2 reduction reaction (CO 2 RR) to valuable multicarbon (C 2+ ) fuels and chemicals presents a promising strategy to mitigate atmospheric CO 2 accumulation and promote the closure of the carbon cycle. However, significant challenges persist in achieving both high product selectivity and sustained stability in the CO 2 RR. In this study, the catalytic performance of (Fe,Co,Ni,Cu) 3 O 4 medium entropy oxide (MEO) nanoparticles anchored on reduced graphene oxide (rGO) was evaluated for the CO 2 RR. The MEO–rGO catalyst exhibited remarkable activity, achieving a cathodic current density of −0.5 A cm –2 at −1.7 V, significantly outperforming bare nickel foam (−0.15 A cm –2 ). Additionally, the catalyst demonstrated a high total Faradaic efficiency (FE) of 60.3% for C 2+ products, comprising 30.6% C 5 H 12 O and 29.7% C 5 H 10 O. This exceptional selectivity toward long-chain hydrocarbons is attributed to the enhanced C–C coupling on the MEO–rGO surface, facilitated by reduced energy barriers. Density functional theory (DFT) calculations further revealed that the adsorption and reduction of CO 2 on the (Fe,Co,Ni,Cu) 3 O 4 MEO surface are energetically favorable processes.