Methane dehydroaromatization using Mo supported on sulfated zirconia catalyst: Effect of promoters

Methane dehydroaromatization (MDHA) is a direct approach of converting methane to aromatics and H2. Mo doped HZSM-5/HMCM-22 are considered as the most active and stable catalysts for MDHA. It is generally thought to involve a process in which Mo oxides convert to MoCy/MoOxCy active species that activate CH4 to C2Hy dimers. In a final step, C2Hy dimers undergo oligomerization on zeolite Br?nsted acid sites. An alternative solid acid support is sulfated zirconia (SZ), which is known to contain strong Br?nsted acidity. Carbon deposition is significant. Here, MDHA is compared to Pt, Pd, Cr, W promoters for Mo/SZ catalyst to decrease carbon deposition and increase aromatics selectivity. The catalysts are characterized using BET, SEM-EDS, DRIFTS, Raman Spectroscopy, XRD, XANES and TPO. Activity varied with different promoters. Less carbon deposition and slower deactivation were observed for Pd, Pt and Cr promoted catalysts, while W promotion resulted in more carbon deposition and rapid deactivation Compared to Pd and W promotion, Pt and Cr increased higher aromatics selectivity for Mo/SZ.

Automated summary

Methane dehydroaromatization (MDHA) is a direct method for converting methane to aromatics and H2, with Mo doped HZSM-5/HMCM-22 being the most active and stable catalysts. Different promoters have varying effects on catalyst activity, carbon deposition, and deactivation rates, with Pd, Pt, and Cr promoters showing less carbon deposition and slower deactivation compared to W promoter. Additionally, Pt and Cr promoters exhibit higher aromatics selectivity for Mo/SZ catalyst compared to Pd and W promoters.