Enzymes that fix nitrogen, make hydrogen and capture CO₂.

We study metalloenzymes — nitrogenases, hydrogenases and their relatives — in the Department of Inorganic and Analytical Chemistry. Our research seeks to understand electron transfer and catalytic mechanisms of enzymes that catalyze these environmentally important reactions. With this understanding, we aim to ultimately couple them to electrode surfaces to (i) have a thermodynamic handle on electron transfer and catalysis, and (ii) apply them to new renewable energy dependent biotechnologies. Our research also informs the design of new bio-inspired catalysts.

The enzymes that we study are not commercially available. Thus, our multidisciplinary research includes bacterial cultivation and protein purification, DNA mutagenesis (i.e., site-directed mutagenesis), mechanistic enzymology, enzymatic electrochemistry/electrocatalysis, and product analysis. In enzymatic electrochemistry, electrodes can be electronically coupled to metalloenzymes in many different ways although the desired outcome remains the same: the electrode supplies the reducing equivalents to the reductive metalloenzyme for subsequent catalysis (or, electrocatalysis) where the corresponding current is related to the rate of substrate reduction by the enzyme.