Development of high-efficiency chemical sensors and catalytic systems through nanostructure engineering of support materials

Abstract

Supported metal catalysts are one of the major breakthroughs in heterogeneous catalysis. Such catalytic systems are broadly being employed in a range of applications including electrochemical reactions, exhaust gas conversion, and chemical gas sensors. However, fabrication of supports materials for the catalysts, especially in the nanometer scale realm with structural versatility remains a challenge to be overcome, for further steps toward catalytic efficiency and activity augmentation. In this Ph.D. thesis, I introduce design strategies for the development of nanostructure-engineered support materials for stabilization of nanocatalysts. The design strategies include (1) electrospinning technique to fabricate one-dimensional nanofibrous structures, (2) a general approach with sacrificial template-assisted synthesis for inorganic nanosheets with high-loading catalysts, and (3) development of single-atom catalysts and its fusion with nanostructure-engineered supports. Nanostructure engineering of the support material brings about greatly increased specific surface area of the overall catalytic system, which in turn increases the number of stabilization sites for higher catalyst loading, as well as increasing the number of active sites for catalytic reactions. In addition, the meso/micropores generated during the synthesis aids more rapid diffusion of reactants, boosting the reaction kinetics for faster reaction speeds. Meanwhile, the single-atom catalysts provide the ultimate maximization of catalyst atom efficiency by allowing the every catalyst atom to take part in the heterogenous catalytic reactions. Combining the mertis of the two strategies of nanostructure engineering of the supports and minimizing the size of the catalysts, our contribution represents an important stepping-stone to a rational design and synthesis of supported catalytic systems with excellent catalytic efficiency.