Catalytic ethanolysis of Hanglaiwan long flame coal to organic small-molecular compounds under mild conditions over SAPO-34-supported nickel nanoparticle catalyst

Abstract

SAPO-34-supported nickel nanoparticle catalyst Ni/SAPO-34 was prepared by a modified deposition-precipitation method and nickel nanoparticles were uniformly dispersed onto the SAPO-34 crystal surface. Hanglaiwan long flame coal (HLFC) was subjected to the catalytic ethanolysis (CE) over Ni10%/SAPO-34 at 300 °C under 1 MPa of initial nitrogen pressure for 4 h to obtain more soluble organic small-molecule compounds (SOSMCs). Ni10%/SAPO-34 can effectively activate ethanol to release H+, +CH2CH3, and H-, and then precisely cleave >CH-O- and >Car-O- bridged bonds in HLFC. As a result, the total yield of soluble portion (SP) increases from 43.2 to 60.5 wt%. Arenes and oxygen-containing organic compounds are the main SOSMCs detected in SPCE from the CE and SPNCE from the ethanolysis, and the yields of arenes, hydroarenes, and phenols in SPCE are higher than those in SPNCE. In addition, compared to SPNCE, the condensation degree of aromatic rings in SPCE is higher. This investigation provides a promising alternative to the clean and value-added utilization of low-rank coals.