Using an advanced physical deposition method, a supported ionic liquid, Et3NHCl center dot CuCl2 immobilized on cyclodextrin modified zeolite, was developed as an efficient desulfurizer. Quantum chemical calculations were employed for the determination of the size of Et3NHCl center dot CuCl2, Et3NH+, and CuCl3-. Et3NH+ can be included into the cavity of beta-cyclodextrin, suggesting that Et3NHCl center dot CuCl2 can be well dispersed on the surface of zeolite. Two deposition modes were proposed due to an excessive molar ratio 7:1 of Et3NHCl center dot CuCl2 to beta-cyclodextrin in favor of H2S removal.