title: Solvothermally-Prepared Cu2O Electrocatalysts for CO2Reduction with Tunable Selectivity by the Introduction of p-Block Elements.
abstract: The electroreduction of CO2to fuels and chemicals is an attractive strategy for the valorization of CO2emissions. In this study, a Cu2O electrocatalyst prepared by a simple and potentially scalable solvothermal route effectively targeted CO evolution at low-to-moderate overpotentials [with a current efficiency for CO (CECO) of ca. 60 % after 12 h at -0.6 V vs. reversible hydrogen electrode, RHE], and its selectivity was tuned by the introduction of p-block elements (In, Sn, Ga, Al) into the catalyst. SEM, HRTEM, and voltammetric analyses revealed that the Cu2O catalyst undergoes extensive surface restructuring (favorable for CO evolution) under the reaction conditions. The modification of Cu2O with Sn and In further enhanced the current efficiency (CE) for CO (ca. 75 % after 12 h at -0.6 V). In contrast, the introduction of Al altered the selectivity profile of the catalyst significantly, decreasing the selectivity toward CO but promoting the reduction of CO2to ethylene (CE≈7 %), n-propanol, and ethanol (CE≈2 % each) at -0.8 V vs. RHE. This result is related to a decreased reducibility of Al-doped Cu2O that might preserve Cu+species (favorable for C2H4production) under the reaction conditions, which is supported by XRD, X-ray photoelectron spectroscopy, and H2temperature-programmed reduction observations.
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093, Zurich, Switzerland.
authors.forename: Gastón O
authors.initials: GO
authors.lastname: Larrazábal
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093, Zurich, Switzerland.
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Martín
authors.affiliation: Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093, Zurich, Switzerland.
authors.forename: Frank
authors.initials: F
authors.lastname: Krumeich
authors.affiliation: EMPA, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600, Dübendorf, Switzerland.
authors.forename: Roland
authors.initials: R
authors.lastname: Hauert
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093, Zurich, Switzerland.
authors.forename: Javier
authors.identifier: 0000-0002-5805-7355
authors.initials: J
authors.lastname: Pérez-Ramírez
mesh_terms: D000535:Aluminum / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D005030:Ethylenes / Q000737:chemistry; D010084:Oxidation-Reduction; D012997:Solvents / Q000737:chemistry*; D014001:Tin / Q000737:chemistry
chemical_list: D005030:Ethylenes; D012997:Solvents; D002245:Carbon Dioxide; D014001:Tin; D003300:Copper; C036216:ethylene; D000535:Aluminum; C000520:cuprous oxide
keywords: CO2 reduction; copper; electrocatalysis; indium; tin