Synthesis and characterization of catalytic nanoporous carbon membranes

A method is reported for the synthesis of novel catalytic nanoporous carbon membranes. Defect-free, nanoporous carbon films of 12.5- mum average thick ness containing a dispersion of Pt-x were synthesized on macroporous stainl ess-steel supports. Ideal gas selectivities for the catalytic membranes wer e similar to those of inert nanoporous carbon membranes with He-N-2 = 58.6 and O-2-N-2 = 4.9. The selective hydrogenation of monoolefins (propylene, 1 -butene, isobutylene) was used to probe the shape-selective catalytic prope rties and the transport selectivities of the membranes. The results were mo deled using the linens regime of coupled adsorption, transport and reaction in the membrane. Model regression yielded 14.9, 19.7, and 18.4 kJ/mol for the activation energies of permeation for propylene, isobutylene, and 1-but ene, respectively The system demonstrated selective reaction and transport favoring propane production with selectivity? ratios of 28.9:3.2:1 for prop ane:n-butane:isobutane at 125 degreesC.