Enhancing mechanisms of N-doped biomass carbon on the vanadium-based catalyst for furan degradation at low temperature

Abstract

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) have attracted widespread concern due to their high toxicity, and their difficult manipulation in laboratories has made the research process tough. Thus, in our work, furan is selected as the model compound owing to the same structure of a central oxygenate ring. Although catalytic oxidation is regarded as an effective and applicable method for the abatement of PCDD/Fs, the synthesis of low-temperature catalysts is still a challenging problem in practical applications. Considering this situation, we prepared a novel V₂O₅/TiO₂ catalyst modified with N-doped hierarchical porous carbon (NHPC) via a wet impregnation method. The V/T-1%NHPC catalyst could achieve expectant low-temperature performances with 50% furan conversion at 150 °C and a complete conversion at 200 °C, which decreased 23 °C and 40 °C compared to the V/T catalyst respectively. Moreover, the addition of NHPC presented lifting chemical stability during long-time test. The addition of NHPC in V/T catalysts decreased the formation of crystalline V₂O₅ and increased the percentages of V⁵⁺ and O_lat, which improved the utilization of vanadium ions and the catalytic activity. Simultaneously, the higher binding energy shift of O_lat implied more reaction possibility with other oxidise reactants. Importantly, this work proved the lifting catalytic activity by the interaction between catalysts and NHPC, and proposed the promoting effects of the N element. The results showed that the content of the pyridinic N and graphitic N in NHPC changed after combining with V/T catalyst, which played crucial roles in the excellent catalytic performance. Overall, this work provides comprehensive research of the V/T-1%NHPC catalyst toward furan oxidation at low temperature and explain the effects of N-doped biomass carbon in catalytic activity clearly, which gave a new thought to design low-temperature catalysts in PCDD/Fs degradation. Besides, the internal functional mechanisms of N species are worth further exploration in future studies.

Graphical abstract