Study on the catalytic performance of ZnCrAl co-precipitated oxides washed with ammonium carbonate solution in the synthesis of light olefins from syngas

Abstract

The activation of carbon monoxide by the presence of oxygen vacancies is widely recognized as a crucial step in the direct synthesis of light olefins from syngas. However, little research has been reported on increasing the concentration of oxygen vacancies on the surface by changing the co-precipitated oxide scrubbing solution. In this study, ZnCrAl oxides were synthesized utilizing an innovative method involving the utilization of ammonium carbonate solution as the washing solution. XPS, NH₃-TPD, BET, and XRD tests were used to look at the samples. They showed that the samples under study have more oxygen vacancies, a more acidic surface, and a larger specific surface area than the water-washed co-precipitated oxides and sol–gel oxides. The quantity of ZnO was decreased. Moreover, there was increased catalytic activity in the investigated samples. When employed as a bifunctional catalyst alongside SAPO-34 for the catalytic reaction of syngas, the conversion of CO was observed to reach 55.48%, while the yield of light olefins reached 28.36%. Because of this, using an ammonium carbonate solution to clean the co-precipitated oxides is a very good idea for further research. This approach offers a new direction to enhance the presence of oxygen vacancies on the oxides' surface and investigate the structural correlation.