An in situ and operando FTIR-DRIFTS-MS analysis of low temperature CDRM reaction

Dry reforming of methane is a very advanced process when it comes to efficient utilization of methane as its product stream can be used to produce many useful end-products. Yet, industrial application of CDRM remains very limited. One of the reasons for this underutilization emerges from the energy-intensive nature of CDRM necessitates the use of high temperatures, hence, the design and development of CDRM catalysts that can work at temperatures lower than 500 °C has been an interesting research topic. The aim of this study is to investigate a low temperature CDRM catalyst through in-situ and operando FTIR-DRIFTS-MS experiments in order to elucidate the mechanism of CDRM at low temperatures. In this context, Ru-La/ZrO2 is prepared and characterized via XRF and XRD. Performance tests were conducted in order to ensure catalyst's activity and stability at low temperature CDRM conditions. Results show that Ru-La/ZrO2 catalyst reached conversion values of 8.4% and 13% for CH4 and CO2, respectively, at 450 °C. CO adsorption, CH4 adsorption, CO2 adsorption and reaction experiments were conducted on Ru-La/ZrO2, La/ZrO2 and ZrO2 samples in FTIR-DRIFTS-MS system. CO adsorption experiments revealed possible CO adsorption sites both at the room temperature and at 450 °C. CH4 adsorption experiments made clear how CH4 gets activated on the catalyst surface while CO2 adsorption work declared carbonates as the dominant surface species adsorbed on ZrO2 support. Reaction experiments on Ru-La/ZrO2 in operando condition revealed a relation between linearly bonded Ru-CO peak and simultaneously recorded MS activity readings. In transient kinetic tests, a tangible connection was explored via analyzing 16 spectra that spans the first minute of time on stream, and deconvoluted peaks of linearly bonded Ru-CO species appeared to be closely related to MS activity readings recorded simultaneously.