Tuning the metal-support interaction on chromium-based catalysts for catalytically eliminate methyl mercaptan: Anchored active chromium species through surface hydroxyl groups

Chromium (Cr) species with different loading (1, 2.5, 5, 7.5 and 10 wt%) were impregnated over alumina (Al 2 O 3 ) and silica (SiO 2 ) supports to investigate the effects of the metal-support interactions on decomposing methyl mercaptan. The characterization results revealed that the amount and nature of surface hydroxyl groups of support (Al-OH and Si-OH) induce the different interactions between chromium species and support, which generates an exceeding support-dependent dispersion, oxidation states, reducibility, and acid-base properties for the prepared Cr-based catalysts. As compared with SiO 2 support, Al 2 O 3 -supported chromium catalysts with evenly dispersed monochromatic Cr(VI) species exhibited excellent catalytic activity by means of theirs enhanced reducibility and sufficient acid-basic sites. Therefore, it is concluded that the metal-support interactions can be tailored by engineering the amount and nature of hydroxyl groups on the support.