Cu based catalysts for syngas production from ethanol dry reforming: Effect of oxide supports

The Cu-based catalysts supported on different materials (CeO2, ZrO2, CeO2-ZrO2) were tested towards syngas production from CO2 reforming of ethanol in order to determine the role of support. The physicochemical properties of the as-prepared catalysts were intensively explored by various techniques such as BET. TPR. Raman. SEM and TEM etc. Noticeably, the key features such as metal-support interaction, the reducibility and the oxygen vacancies decreased in the following order: CuCeZr > CuCe > Cu/Zr. Among the investigated catalysts, analysis of ethanol conversion as well as evaluation of the product distribution suggested CuCeZr sample as the most appropriate system for ethanol dry reforming. More precisely, CuCeZr catalyst exhibited full ethanol conversion at 700 degrees C and the H-2/CO ratio was close to the theoretical one (1.0). It also showed the promising stability as long as 90 h time-on-stream. In addition, the reliance of ethanol turnover frequency (TOF) on the supports was noted and CuCeZr sample still presented the highest value versus that of the others. Characterization results of the used catalysts indicated that both the smaller extent of Cu sintering and the less deactivating coke formation was observed for CuCeZr catalyst after the stability test, because of its abundant oxygen defects and/or sufficient metal-support interfacial area. It should be noted that the nature of carbonaceous deposits on the used CuCeZr catalysts were mainly amorphous structure. In contrast, the encapsulating coke which was detrimental for catalyst behavior was obviously detected. Herein, the present work revealed that support played an important role in ethanol dry reforming and might provide some valuable insight for the development of efficient catalysts.