Synthesis of a novel catalyst with nano metal core/carbon shell by a facile pre-complexation strategy and its application in enhanced catalytic decomposition of nitric oxide

- A pre-complexation strategy was used to synthesize catalyst.
- A nano metal core/carbon shell catalyst was obtained.
- The catalyst removed ∼100% of NO for more than 1000 min.
- The NO was catalytically removed by dual mechanisms.
- Solid and gaseous active species accounted for the enhanced activity.

In this work, a novel and facile pre-complexation strategy was reported for the synthesis of carbon-metal catalyst for the first time. The carbon-metal catalyst (SF250) was obtained by thermal-activating pre-complexation of ferric chloride and sodium salicylate. The HRTEM and XRD showed that SF250 contained nanometer particles with core of FeOOH and shell of carbon species. When SF250 was applied in selective catalytic reduction of nitric oxide (NO), it resulted in outstanding efficiency and long-term stability: the removal of NO was 99.8% with a fluctuation of 0.8%; moreover, the SF250 maintained high efficiency of removal for more than 3000 min at 400 °C. The analyses of EELS and TG-MS suggested that solid-phase and gas-type carbons both participated in reduction of NO, thus resulting in the excellent activity at low temperature. The solid-phase carbon included the active species with great reducibility distributed on the core-shell interface. The gas-type carbon included CO and benzene radicals. Therefore, our work has suggested a novel method for the synthesis of catalyst with core-shell structure by simple operation and low-cost precursors, together with excellent activity toward catalytic reduction of NO.

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