Alkylsulfonic acid functionalized aluminoborate: A highly efficient and regioselective solid acid catalyst for ring-opening addition of epoxide under solvent-free condition

Functionalized solid acid material has more accessible active surface and therefore is usually considered as an important substitute for conventional liquid mineral acid. In this work, a novel alkylsulfonic acid functionalized porous aluminoborate molecular sieve (PKU-1) has been prepared through 3-step post-synthetic method, and the high-density acidic sites were tailored and comprehensively characterized by various measurements. These acidity-controllable active sites exhibit high activity and specific regioselectivity towards alcoholysis reaction for the solvent-free production of methoxyl alcohol, and turnover frequency reaches similar to 1000 h(-1), which is much superior to previous reports. Comprehensive characterizations indicate catalytic centers exclusively come from -SO3H acid sites, rather than other type of Br & ouml;nsted or Lewis acid sites. A plausible reaction mechanism was proposed to interpret the key role of -SO3H active sites on alcoholysis reaction based on the related experimental results. This work offers a promising solution to generate the controllable acidity and provides an available candidate in the environmentally benign catalysis for selective synthesis of some value-added compounds.