초록 |
MTH process has received great attention in the petrochemical industry on the purpose of minimizing greenhouse gas and petroleum dependence. However, severe catalyst deactivation due to coking is a major problem for their application in commercial MTH plants. To overcome this, a gadolinium (Gd)-promoted ZSM-5 catalyst exhibited good anti-coking characteristic during hydrocarbon cracking reaction. We report the role of Gd as a coke inhibitor and suggest stategic design of the Gd-promoted catalyst for the MTH reaction. Gd atoms decrease the acidity and increase the basicity of the parent ZSM-5 catalyst to prevent fast deactivation and adsorption of coke intermediates, such as carbenium and carboxylate ions, onto the catalyst surface during the MTH reaction. Those synergetic effects impede the adsorption and growth of coke intermediates, leading to an improved catalyst life time without changing catalytic activity or product selectivity. |