On the assessment of electrocatalysts for nitrate reduction

The electrochemical reduction of nitrate is attracting attention in the context of producing ammonia, besides the traditional removal to harmless N₂. To make progress in this complex reaction and facilitate the search for active and selective catalysts, we need to establish generalized testing protocols which will enable to compare and complement data from different laboratories. The purpose of this article is to raise awareness on the importance of (i) solution processes that involve products of the electrode reaction, (ii) determination of products with appropriate, product-specific quantitative methods, (iii) the strong sensitivity of the reaction on experimental parameters, (iv) the cell design for the separation of anode from cathode processes, and (v) the increase in the interfacial and solution pH that occurs during the electrolysis at high current densities.