Facile Transformation of Ni-based Colloids into Highly Stable Nanocatalysts Embedded within h-BN for the Water-Gas Shift Reaction

Advances in colloidal chemistry allow to prepare well-controlled nanostructures, while application of the colloids in heterogeneous catalysis is strongly impeded by the presence of organic capping layers. However, removal of the protection layers inevitably results in changes of the well-defined nanostructures such as sintering and agglomeration. Here, a simple way is suggested to solve the dilemma by replacing the organic capping layers with another flexible but robust capping layers made of two-dimensional materials. We show simultaneous removal of surfactant layers in B-containing Ni, Co, and Fe colloids and formation of hexagonal boron nitride (h-BN) capping layers over metal nanoparticles. Metal particle size can be well kept even upon thermal treatment at 850 degrees C and Ni nanocatalysts embedded within h-BN shells present high catalytic performance in water-gas shift reaction. This work suggests a facile strategy to promote the application of metal colloids in heterogeneous catalysis.