Efficient utilization of vermiculite modified waste liquid: Hydrotalcite-derived catalyst for methane dry reforming and its mechanism

Dry reforming of methane (DRM) is an effective method for carbon capture, as it simultaneously utilizes atmospheric methane and carbon dioxide to convert these gases into high-value syngas. Vermiculite-based hydrotalcite-derived Co(Fe,Cu)/Ni catalysts were prepared using a vermiculite-modified waste fluid modulation technique and employed in the DRM reaction. The Co/Ni-VMT-LDO catalyst demonstrated excellent activity and stability during the DRM stability test conducted at a temperature of 750 °C and an air velocity of 60,000 mL/(g⸱h). Over the 24-h test, CO 2 conversion stabilized at 81 %, while CH 4 conversion stabilized at 71 %. The catalyst was characterized using XRD, H 2 -TPR, N 2 -sorption desorption, and TEM techniques. The results indicate that Co/Ni-VMT-LDO exhibits high catalytic activity and stability, which can be attributed to the homogeneous composition of the Ni–Co alloy, appropriate particle size, strong metal-carrier interaction, and the presence of Mg(Ni,Al)O as a carrier. These factors contribute to the catalyst's resistance to carbon deposition and sintering. Furthermore, in situ DRIFTS characterization revealed that surface-adsorbed O∗ species can bind to CH X , thereby reducing carbon accumulation on the catalyst surface. The elimination of carbon buildup is crucial for the efficiency of the DRM reaction. • The catalyst derived from vermiculite waste liquid has been successfully synthesized. • The Co/Ni-VMT-LDO catalyst exhibits excellent DRM performance. • The reaction mechanism of DRM follows the Langmuir-Hinshelwood model.