Orange Peel Biomass-derived Carbon Supported Cu Electrocatalysts Active in the CO 2 -Reduction to Formic Acid.

We report a green, wet chemistry approach towards the production of C-supported Cu electrocatalysts active in the CO 2 reduction to formic acid. We use citrus peels as a C support precursor and as a source of reducing agents for the Cu cations. We show that orange peel is a suitable starting material compared to lemon peel for the one-pot hydrothermal synthesis of Cu nanostructures affording better Cu dispersion as well as productivity and selectivity towards formic acid. We rationalize this finding in terms of the beneficial chemical composition of the orange peel, which favors both the reduction of the Cu precursor as well as the carbon matrix. This work demonstrates new viable opportunities for the reuse of citrus waste on a rational basis.