Chementator: A new method for catalyst design  

A method for identifying less-expensive catalysts, compared to commercial, precious-metal-based ones, is starting to deliver results by researchers at the Center for Atomic-scale Materials Design, Dept. of Physics, Technical University of Denmark (CAMD; Lyngby; www.camd.dtu.dk) and their collaborators. The computer-aided method ultimately generates a plot of cost-of-metal versus heat of adsorption for the molecule to be catalyzed. From this graph, new catalysts with promising reactivity and selectivity can be identified before doing a single laboratory experiment. The method starts by performing density function calculations to identify scaling relations between different adsorption energies of reactants and intermediates on metal surfaces. From these scaling relations (which are linear for simple molecules such as methane, ammonia and C2 hydrocarbons), it is possible to identify a descriptor — to borrow a term from biotechnology — for both catalytic activity and selectivity, explains Jens Nørskov, physics professor and director of CAMD. As a test example, the researchers investigated the selective hydrogenation of acetylene in mixtures of acetylene and ethylene — an industrially relevant problem for polyethylene…