Photocatalytic removal of the greenhouse gas nitrous oxide by liposomal microreactors

Nitrous oxide (N₂O) is a potent greenhouse and ozone-reactive gas for which emissions are growing rapidly due to increasingly intensive agriculture. Synthetic catalysts for N₂O decomposition typically contain precious metals and/or operate at elevated temperatures driving a desire for more sustainable alternatives. Here we demonstrate self-assembly of liposomal microreactors enabling catalytic reduction of N₂O to the climate neutral product N₂. Photoexcitation of graphitic N-doped carbon dots delivers electrons to encapsulated N₂O Reductase enzyme via a lipid-soluble biomolecular wire provided by the MtrCAB protein complex. Within the microreactor, electron transfer from MtrCAB to N₂O Reductase is facilitated by the general redox mediator methyl viologen. The liposomal microreactors use only earth-abundant elements to catalyze N₂O removal in ambient, aqueous conditions.