RESUMO
Herein we report a biomimetic triruthenium catalyst that, when under direct sunlight irradiation, facilitates high-rate H2 production from formic acid (FA) dehydrogenation. The system consists of 2 µmol of catalyst and 6 µmol of tri- o-tolylphosphine in 1 mL of dimethylformamide (DMF) and 4 mL of FA/triethylamine (TEA; 5:2). With 0.4 mM catalyst loaded, a high turnover frequency of 1.15 × 106 h-1 was detected when under direct sunlight irradiation. In an experiment with 0.2 mM catalyst loaded, more than 140 L of H2 (280 L of H2 + CO2) was produced, and a turnover number of approximately 2.78 × 106 was obtained within 5 h without decline in H2 generation activity, making it suitable for high-rate H2 production.
RESUMO
A ruthenium-based biomimetic hydrogen cluster, [Ru2 (CO)6 (µ-SCH2 CH2 CH2 S)] (1), has been synthesized and, in the presence of the P ligand tri(o-tolyl)phosphine, demonstrated efficient photocatalytic hydrogen generation from formic acid decomposition. Turnover frequencies (TOFs) of 5500 h(-1) and turnover numbers (TONs) over 24 700 were obtained with less than 50 ppm of the catalyst, thus representing the highest TOFs for ruthenium complexes as well as the best efficiency for photocatalytic hydrogen production from formic acid. Moreover, 1 showed high stability with no significant degradation of the photocatalyst observed after prolonged photoirradiation at 90 °C.