Chemical Society NATURAL MATERIALS MODIFIED WITH TRANSITION METALS OF THE COBALT GROUP: FEASIBILITY IN CATALYSIS

The chemical modification of a clinoptilolite-mordenite natural zeolite mixture (in a ratio close to 1) from an Argentinean deposit was done by means of different treatments. The procedure started with the exchange with ammonium and further heating at 400ºC to form an acid-zeolite mixture (indirect method). The treatment with Co(II) and Rh(III) aqueous solutions (by soft chemical process) led to modified zeolites containing 0.38 % Co(II) and 0.25 % Rh(III). These materials heated at 500ºC were proved as catalysts in the NO Selective Catalytic Reduction (SCR) process using propane as reducing gas. Physico-chemical characterization by different analytical techniques and the catalytic activity tests for the mentioned reaction were interesting to point out the technological potentiality of abundant and low cost natural species under inorganic treatments. Key words: natural zeolites, chemical modification, catalysis, NO SCR process..M. E. Canafoglia et al. 5