Improving the electrocatalytic N2 reduction activity of Pd nanoparticles through surface modification

Industrially, NH3 production mainly relies on the energy-intensive Haber-Bosch process with the release of a large amount of CO2. Electrochemical fixation of N-2 to NH3 under ambient conditions is an environmentally friendly and sustainable alternative, but the N-2 reduction reaction (NRR) requires stable and efficient electrocatalysts. In this work, we report that the electrocatalytic NRR activity of Pd nanoparticles can be improved by surface modification with oxygen-rich tannic acid. The electrochemical test results in 0.1 M Na2SO4 suggest that such a catalyst achieves a large NH3 yield of 24.12 mu g h(-1) mg(cat.)(-1) and a high faradaic efficiency of 9.49% at -0.45 V vs. the reversible hydrogen electrode (RHE), rivaling the performances of most of the reported aqueous-based NRR electrocatalysts. In addition, it also shows strong long-term electrochemical stability.