Synergetic effect of tin and potassium modifying additives on rhodium catalysts in the process of selective dehydrogenation of associated petroleum gas

This paper presents the results of an investigation into the catalytic activity and selectivity of rhodium-based catalysts supported on natural zeolite clinoptilolite from the Shankanai field (Kazakhstan) in the dehydrogenation of light alkanes from associated petroleum gas (APG). Three modifications of the catalyst have been studied: basic 1%Rh/HCpt, modified with tin 1%Rh/10%SnO/HCpt, and combined with additives of tin and potassium 1%Rh/10%SnO/5%K2O/HCpt. It has been shown that the addition of tin contributes to increased thermal stability and a decreased coking rate, while the addition of potassium suppresses side reactions (cracking and isomerization), increasing the selectivity for olefins. The highest yield of olefins (~30%) is achieved with the 1%Rh/10%SnO/5%K2O/HCpt catalyst in the presence of water vapor. Using scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), improved distribution of active components and reduced catalyst deactivation have been confirmed. The obtained data demonstrate the potential of the developed systems for the efficient processing of APG and the selective synthesis of olefins.