INFLUENCE OF THE NATURE OF TRANSITION METAL ON ACID-BASE PROPERTIES OF THE SURFACE AND ACTIVITY OF CATALYSTS BASED ON NATURAL CLINOPTILOLITE IN THE REACTION OF BIOGAS CONVERSION TO SYNTHESIS GAS
Catalysts based on natural clinoptilolite modified by transition metals (Ni, Co, Cr, Mo, Fe) were studied in the reaction of biogas conversion to synthesis gas. A particular attention is paid to exposing of relationship between acid-base properties surface - activity. This was achieved by studying the effect of the introduced transition metal nature on the acid-base spectrum and comparing the data obtained with sample activity. The highest activity and selectivity of the nickel sample has been established, that makes it possible to achieve complete methane conversion at 7000C to obtain synthesis gas with the ratio H2/CO = 1. It has been shown that the increased catalytic activity of the nickel sample is provided by an optimal combination of acid-base properties of the surface. It was found that the nickel sample is characterized by the presence of weak acid (electron-acceptor) centers with ionizing force of 9.69±0.01 eV, medium-acid (proton-donor) centers with ionizing force of 10.59±0.01 eV, and weak basic centers capable of ionizing a particle with dissociation constant of 9.89±0.01 that distinguish it from other samples