Ruthenium Catalyzed Reduction of N 2 O using MeOH as Hydrogen Source

Nitrous oxide (N 2 O) is a significant contributor to climate change owing to its dual role as greenhouse gas and ozone-depleting molecule. Herein, the catalytic reduction of N 2 O to N 2 using methanol (MeOH) as a terminal reductant was investigated employing a series of Ru complexes supported by proton-responsive picoline- and lutidine-derived pincer ligands incorporating N-heterocyclic carbene donors (CNC and CNN). Among the complexes examined, a Ru catalyst featuring a picoline-derived CNN ligand incorporating a secondary amine functionality displayed the highest activity, achieving turnover numbers (TONs) up to 417 after 72 h, in the reduction of N 2 O to N 2 . Under catalytic conditions, the formation of metal nanoparticles from this catalytic precursor was observed. These nanoparticles were independently synthesized and found to be catalytically active in the reduction of N 2 O with MeOH. Finally, control experiments further demonstrated that both homogeneous and nanoparticle species contribute to the overall catalytic process, participating in the methanol reforming and N 2 O reduction steps.