Adsorption of NOx by graphene oxide loaded with CeO2 as a catalyst for atmospheric pollution control

Abstract

In this study, we utilized graphene oxide (GO) loaded with cerium oxide (CeO2) to synthesize GO-CeO2 catalysts using a hydrothermal method and high-temperature calcination. The performance of the catalyst was evaluated by characterization of the catalyst material and testing for nitrogen oxide (NOx) conversion rates and nitrogen gas adsorption isotherm in mixed flue gas. The results demonstrated that increasing the ratio of NO2 in the NO+NO2 mixture significantly enhanced the conversion rate of NOx. Notably, when the proportion of NO2 reached 0.4, the denitrified gas displayed a remarkable increase in NOx conversion rate, exceeding 98%. This finding highlighted that even low concentrations of NO2 can accelerate denitrification reactions. Moreover, increasing the oxygen concentration in the gas exhibited considerable potential to elevate the NOx conversion rate. The oxygen concentration played a vital role in the process of denitrification, and the GO-CeO2 catalyst exhibited a high oxygen storage capacity. Moreover, the GO-CeO2 catalyst maintained a high denitrification efficiency even under high-temperature conditions and demonstrated excellent NOx conversion performance. The catalyst also demonstrated good stability and strong water resistance under varying proportions and temperatures while maintaining a consistent denitrification efficiency. These findings indicated the significant adsorption effect of the graphene oxide loaded with CeO2 catalyst on NOx, suggesting promising potential for application and widespread use.