Electrocatalysis is a branch of catalysis dealing with the enhancement of chemical reactions occurring at an electrode (known as electrocatalyst). Electrocatalytic materials are designed to overcome reaction bottlenecks affecting the kinetics (sluggish reaction rate), and to steer selectivity to the desired product(s). Transition metals and enzymes have been widely investigated as individual electrocatalysts. The aim of TEAMCat is to tap into the synergistic catalytic effect of metals and enzymes by designing a twinned catalyst, in the form of metal nanoparticles and enzymes co-deposited on carbon. The twinned catalysts will act as in a relay: the selected enzyme will produce in situ the substrate of the metal catalyst, thus sidestepping the rate-determining step of the latter. This cascade action is expected to accelerate the overall reaction rate. In parallel, mechanistic studies are crucial in pinpointing the molecular basis of electrocatalysis. In this respect, TEAMCat aims to investigate the reaction intermediates and products by combining electrochemistry with infrared spectroscopy. This will exploit a specific IR configuration (ATR-IR) for addressing carbon supported catalysts, developed in the Vincent group for immobilised biocatalysts, and now extended to supported metal nanoparticles. Not only will the project provide mechanistic insight, but the extension of this technique will represent significant progress in terms of the in situ study of supported electrocatalysts, such as those applied in fuel cells. The first reaction targeted by TEAMCat will be electrocatalytic nitrate reduction, which plays a key role in environmental chemistry, since electrocatalysis is a promising tool for the remediation of nitrate-laden water. After showing proof-of-concept twinned catalysis, TEAMCat will move on to investigate the catalysis of carbon dioxide reduction, aiming to make further inroads to efficient conversion of the greenhouse gas into useful hydrocarbons.