PNNL

Abstract

Selective removal of heterocyclic organosulfur compounds from fuels can relieve increasingly serious environmental problems (e. g. gas exhaust contaminants triggering the formation of acid rain that can damage fragile ecological systems). Toward this end, we designed and synthesized novel MOF-based sorbent materials with distinct hard and soft metal building units, specifically {[Yb6Cu12(OH)4(PyC)12(H2O)36]·(NO3)14·xS}n (QUST-81) and {[Yb4O(H2O)4Cu8(OH)8/3(PyC)8(HCOO)4]·(NO3)10/3·xS}n (QUST-82), where H2PyC = 4-Pyrazolecarboxylic acid. Exploiting the hard/soft duality, we show the more stable QUST-82 can selectively remove organosulfur in the presence of competing nitrogen-containing contaminate. In addition, we uncovered a thermodynamically-controlled single-crystal-to-single-crystal (SC-SC) phase transition from QUST-81 to QUST-82, and, in turn, probed mechanistic features via XRD, ICP-AES and ab initio molecular dynamics (AIMD) simulations. This work was supported by the National Natural Science Foundation of China (No. 21601102), the Natural Science Foundation of Shandong Province (No. ZR2016BQ34), the Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, U.S. Department of Energy, under Award KC020105-FWP12152. PNNL is a multiprogram national laboratory operated for the U.S. Department of Energy by Battelle Memorial Institute under Contract DE-AC05-76RL01830. This research used resource of the Advanced Light Source, which is a DOE Office of Science User Facility under contract no. DE-AC02-05CH11231. Simulations were performed using PNNL Institutional Computing Resources. Y.H also thanks the “International Postdoctoral Exchange Fellowship Program” (No. 20170035).