Integrated Sensor for Detecting Hydrogen Concentration as Proxy for Ethylene and Propylene Production Using Pt–Fe and Pt–Cu Catalysts

The increasing demand for ethylene and propylene has stimulated extensive research on propane dehydrogenation (PDH) for short-chain olefin production.However, catalyst deactivation and limited real-time monitoring remain key challenges in microwave-assisted PDH systems.In this study, we investigated waste-derived Pt-based bimetallic catalysts (Pt-Fe and Pt-Cu) and evaluated the feasibility of integrating real-time hydrogen sensing for in situ process monitoring.Waste Pt catalysts were recycled and modified with Fe and Cu, and combined with microwave-absorbing microparticles to enhance energy utilization and catalytic performance.Reactions were conducted at 450 W for 360 min with a propane feed rate of 10 mL/min.Hydrogen concentration was continuously monitored using a Siemens Calomat 62 sensor installed in the tail gas line, enabling the real-time evaluation of catalyst activity and deactivation behavior.This work presents a novel strategy by integrating sustainable Pt catalyst recycling with in situ hydrogen sensing for microwave-assisted PDH monitoring.The Pt-Fe catalyst produced 7.5% ethylene and 3.0% propylene with 69.4% hydrogen, whereas Pt-Cu exhibited superior performance with 9.5% ethylene, 11.9% propylene, and 78.8% hydrogen.SEM analysis revealed distinct coke morphologies associated with catalyst deactivation.The results demonstrate that combining bimetallic catalyst modification with hydrogen sensing significantly improves process monitoring and performance evaluation in microwave-assisted PDH systems.Further studies on long-term stability and scale-up are required for industrial application.