Efficient catalytic elimination of COS and H2S by developing ordered mesoporous carbons with versatile base N sites via a calcination induced self-assembly route. (10th August 2020)

• Record Type: Journal Article
• Authors: Liang, Shijing; Mi, Jinxing; Liu, Fujian; Zheng, Yong; Xiao, Yihong; Cao, Yanning; Jiang, Lilong
• Is Part Of: Chemical engineering science. Volume 221(2020)
• Publication Date: 2020-08-10
• Subjects: Ordered mesoporous carbons -- Calcination induced self-assembly -- Structural base N sites -- COS catalytic hydrolysis -- H2S selective oxidation; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2020.115714
• Languages: English
• ISSNs: 0009-2509

Abstract

Graphical abstract: A calcination induced self-assembly route was developed to synthesize ordered mesoporous carbons with structural base N sites without any involvement of solvent and catalyst. The samples act as high-efficient and reusable catalysts for H2 S and COS elimination to elemental sulfur. Highlights: Solvent-free calcination induced self-assembly (S-CISA) route was developed. S-CISA was used to design ordered mesoporous carbon with structural base N sites. Structural base N sites in the samples were very active for removal of COS and H2 S. The catalysts show enhanced mass transfer and high capacities for H2 S capture. Synergistic effect of base N sites and H2 O2 specie was proposed in H2 S oxidation. Abstract: Catalytic elimination of highly toxic COS and H2 S from industrial resources plays a crucial role in terms of production safety and environmental protection. We report here novel calcination induced self-assembly concept to the fast synthesis of ordered mesoporous carbons with structural base N sites (A-N-OMC-Ts, where T stands for carbonization temperature) without using any solvent and catalysts. The A-N-OMC-Ts show large BET surface areas (∼1538 m 2 /g), ordered mesoporosity, and the base N sites exhibit versatile structures (e.g. pyridine and pyrrole, 2.03–3.77 wt %). As a result, A-N-OMC-Ts show excellent activities in hydrolysis of COS to H2 S, and the H2 S can be efficiently captured (∼10.5 mmol/g, 0 °C, 1 bar, IAST selectivity H2 S/N2 = 4963, 75 °C) and oxidized into elemental sulfur by A-N-OMC-Ts. The complete elimination of COS and H2 S over A-N-OMC-Ts was performed at ambient conditions (50 °C for COS; 150 °C for H2 S, and Ea = 32.29 kJ/mol), much better than that of g -C3 N4 (150 °C, H2 S conversion < 10%, Ea = 42.11 kJ/mol). These performances are outstanding among the metal-free catalysts reported previously. A plausible mechanistic scenario involves the synergistic effect of pyridinic and pyrrolic N as well as the intermediate H2 O2 was proposed by us. Coupled the cleavage of H-S bond and S release that accelerate the desulfuration rate.