(756f) Design of Bimetallic Catalysts for Alkane Selective Dehydrogenation

Light olefins such as ethylene and propylene are very important products in industry, and they have essential application in for example the production of plastics. However, the current worldwide capacity is unable to fulfill the increasing market demand of estimated 300 million tons by 2020. The conventional noncatalytic process based on steam cracking of alkanes at high temperature still dominates the ethylene and propylene production despite of its low selectivity and high energy-intensity. Nevertheless, due to the technological development in fracking, the large availability of cheap ethane and propane from shale gas exploitation has provided opportunities for on-purpose ethylene/propylene productions such as catalytic ethane dehydrogenation and propane dehydrogenation with the advantages of high selectivity and energy efficiency. However, the key challenge of this process faces a common hurdle in heterogenous catalysis, that is, design of an active, selective, stable and inexpensive catalyst. Currently, a Pt-Sn alloy is regarded as the most promising catalyst possessing all of the above merits except for low cost. The experimental ‘trial-and-error’ strategy for catalyst design lacks efficiency and prolongs the period of new catalyst discovery. In this respect, efficient catalyst screening methods are highly desirable, among which the descriptor-based micro-kinetics analysis of general catalytic trends across various catalysts has proven to be effective and useful. In this work, an improved decision map is developed by combining the activity and selectivity volcanos from micro-kinetic modeling, which is based on specific acquisition functions for the EDH reaction. Accurate calculations were performed on 1998 bimetallic alloys and via high-throughput screening a group of promising noble-metal free bimetallic alloy catalysts for selective EDH were identified. We believe these predicted candidates will provide essential references for further development of EDH catalysts for practical applications.