Carbon-Supported Potassium Hydride for Efficient Low-Temperature Desulfurization

The industrial removal of organosulfur impurities from fossil fuels relies on transition-metal-based catalysts in harsh conditions (ca. 400 degrees C, up to 100 bar H-2), yet desulfurization (DS) of refractory alkyl dibenzothiophenes (DBTs) remains challenging. Here, we report that carbon-supported potassium hydride (KH/C) enables efficient DS of DBTs in mild conditions, viz. >97 % conversion of DBTs is achieved at 165 degrees C in 3-6 h while the yields of respective biphenyls are 84-95 % by using only 15 % excess of KH per a C-S bond. In addition, KH/C allows to lower the concentration of 4,6-Me2DBT in the mesitylene solution from 1000 ppm to <3 ppm (165 degrees C, 20 h) and provides deoxygenation, denitrogenation and catalytic aromatic hydrogenation reactions. DS of various sulfur heterocycles by using KH/C, a transition-metal-free material based on earth abundant elements, is viable at low temperature and has prospects for the further development towards decentralized removal of organosulfur species from fossil fuels.