Carbon‐Supported Potassium Hydride for Efficient Low‐Temperature Desulfurization

Abstract

The industrial removal of organosulfur impurities from fossil fuels relies on transition‐metal‐based catalysts in harsh conditions (ca. 400 °C, up to 100 bar H2), 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 °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 °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.

Production of Benzene by the Hydrodemethylation of Toluene with Carbon‐Supported Potassium Hydride

“…Since K/C transforms to KH/C under an H 2 atmosphere, [23] we tested commercial KH and graphite‐supported KH (obtained from 30 wt % K/C and H 2 ) in the HDM of toluene. [24] Both materials gave products 2 – 4 but with notably different yields; the amount of benzene obtained using KH/C was around sixty times higher than that with commercial KH (Table 1 , entries 8 and 9). Interestingly, 12.2 equiv.…”