Catalytic performance of the modified H-ZSM-5 zeolite in methanol transformation to hydrocarbons

Abstract

In the current work, we present the study of the catalytic performance and characterization of the modified H-ZSM-5 zeolite for methanol to hydrocarbons process. The modification of zeolite was performed by both alkali and acid treatment. The changes in the zeolite structure were studied using low-temperature nitrogen physisorption, NH3 chemisorption, and X-Ray photoelectron spectroscopy. It was found that the zeolite modification with oxalic acid (0.01 M) resulted in the lower catalytic activity loss (48%) after 120 h on stream as compared to both initial and alkali treated H-ZSM-5. Further, the chosen zeolite sample was modified with Co, Fe, and Ni by wet impregnation with the corresponding metal nitrates. The Ni-containing catalyst showed the highest catalytic performance in time on stream. The decrease in the methanol transformation rate for the Ni-containing zeolite was found to be only 27%. The metal-containing catalysts showed the minimal coke formation as well as the minimal decrease in acidity and surface area as compared to the initial zeolite and the samples treated with both alkali and oxalic acid.