Metal-organic framework-derived indium nanotubes for CO2 electroreduction to formate

Electrochemical conversion of CO2 to chemicals is an appealing route to reduce carbon emission and achieve carbon neutrality. Indium (In) is a promising electrocatalyst for CO2-to-formate conversion due to its high selectivity to formate, but is still hindered by low current density and poor stability. In this work, we propose the construction of In nanotubes from MIL-68(In) metal-organic framework nanotubes by a electrolytic route, which is simple, rapid and low-cost. Benefiting from the nanotube morphology and abundant unsaturated coordination In sites, the as-synthesized In nanotubes exhibit high performance for the electrochemical CO2-to-formate conversion. The formate Faradaic efficiency can reach 98.6% at -1.2 V versus reversible hydrogen electrode by using 0.5 M KHCO3 aqueous solution as electrolyte in H-cell, with current density of 24.8 mA cm-2.