Adjusting the host-guest interaction to promote KNO₃ decomposition and strong basicity generation on zeolite NaY

A new strategy was utilized to prepare strongly basic zeolite through precoating MgO on the zeolite NaY prior to KNO₃ modification. By controlling the loading amount of the precursor magnesium acetate, MgO could be well dispersed on NaY as long as its content did not exceed 12 wt%. The precoated MgO layer played a significant role in enhancing the basicity of zeolite by adjusting the host-guest interaction to promote the decomposition of KNO₃ on NaY, and at the same time this MgO layer prevented the zeolite framework from corroding by the resulting strongly basic potassium species. As a result, a strong basicity was successfully generated on NaY, and the resulting basic zeolites containing potassium species exhibited good catalytic performance on the vapor phase methylation of cyclopentadiene (CPD) with methanol. The conversion of CPD was 30.1% and 3.5% over parent NaY and Mg₁₂Y, respectively, accompanied with the methylcyclopentadienes (MCPD) selectivity of 8.3% and 46.1% at the reaction temperature of 500 °C and time of 1 h. However, 38.1% of CPD could be converted over K₁₀Mg₁₂Y under the same reaction conditions, and the selectivity of MCPD achieved to 76.7%.