Regulation of the electrocatalytic nitrogen cycle based on sequential proton–electron transfer

The selective transformation of nitrogen compounds is a foundation of the modern chemical industry. Existing thermochemical processes largely rely on fossil fuels and innovating electrocatalytic processes that could use renewable energy remains challenging. Here we report the electrochemical regulation of a nitrite reduction network using a molybdenum sulfide catalyst by modulating the thermodynamic driving force of proton and electron transfer. The strategy behind this approach is based on the theory of sequential proton–electron transfer, in which the driving force of proton and electron transfer can be optimized independently. This makes it possible to target the desired reactions with selectivities of up to 80% for NO, 61% for N2O, 36% for N2 and 100% for NH4+, comparable to the highest values reported to date using a specific catalyst optimized for a single target product. Consistency with numerical simulation highlights that sequential proton–electron transfer can be used to rationally regulate the electrochemical nitrogen network.