Activating Bi p-orbitals in Dispersed Clusters of Amorphous BiOx for Electrocatalytic Nitrogen Reduction

Catalytic strategies based on main group metals are significantly less advanced than those of transition metal catalysis, leaving untapped areas of potentially fruitful research. We here demonstrate an effective approach for the modulation of Bi 6p energy levels during the construction of atomically dispersed clusters of amorphous BiOx. Bi oxidation state is proposed to strongly affects the nitrogen fixation activity, with the half-occupied p(z) orbitals of the Bi2+ ions being highly efficient toward electron injection into the inert N-2 molecule. With sufficient catalytic sites to adsorb and activate N-2, the bonding between N-2 and catalyst is able to be in situ identified. The catalyst shows an outstanding Faraday efficiency (approximate to 30 %) and high yield (approximate to 113 mu g h(-1) mg(cat)(-1)) in NH3 production, outperforming most of the existing catalysts in aqueous solution. These results lay the basis for developing the potential of p-block elements for catalysis of multi-electron reactions.