Endowing Cu-BTC with Improved Hydrothermal Stability and Catalytic Activity: Hybridization with Natural Clay Attapulgite via Vapor-Induced Crystallization

Metal-organic frameworks (MOFs) have drawn much attention for their highly promising applications, but the applications are often obstructed by the congenitally hydrothermal instability of the MOFs. Hybridizing the MOFs with other materials has been proved to be effective to solve the hydrothermal problems. Herein, a vapor-induced crystallization (VIC) method is employed for the first time to fabricate the hybrid MOFs based on the Cu-BTC and the natural clay attapulgite (NCA). Compared with the traditional solvothermal method for the hybridization, the VIC one has the obvious advantages of both reducing the solvent consumption and inducing the crystals self-repairing to generate perfect crystals of the hybrid MOFs. With an appropriate content of the NCA, the hybrid MOFs are proved to be highly stable even undergoing the hot water vapor (90 °C) for 12 h. The hybrid MOFs also exhibit the improved catalytic activity in catalyzing the styrene oxide ring-opening. The molar conversion of the styrene oxide over the hybrid MOF reaches 93.8% within 20 min, even higher than that of the unadulterated Cu-BTC (68.0%). These results indicate the promising application of the hybrid MOFs as the hydrothermal-stable and highly active heterogeneous catalysts.