Nitrogen-Decorated, Ordered Mesoporous Carbon Spheres as High-Efficient Catalysts for Selective Capture and Oxidation of H₂S

Abstract

Hydrogen sulfide (H2S) is highly toxic and corrosive, and its selective removal from fuel and flue gases is of significance. It is a challenge to develop a dual-role material for efficient H2S capture as well as selective H2S oxidation. In the present work, we designed a class of nitrogen-decorated ordered mesoporous carbon spheres (denoted herein as N-OMCS-T, where T stands for carbonization temperature) for such an end. The N-OMCS-T with ordered mesopores are large in BET surface area (1201–1500 m2/g), and enriched with nitrogen sites of pyridinic and pyrrolic nature, and exhibit strong interaction with H2S as verified in DFT calculations. With large BET surface areas, ordered mesopores, and abundant nitrogen sites, the N-OMCS-T materials show extraordinary efficacy for the capture of H2S: H2S capacities are up to 13.4 mmol/g (0 °C, 1 bar), and the Ideal Adsorption Solution Theory selectivity in cases of H2S/​CO2, H2S/​CH4, and H2S/​N2 is 2.1–8.5, 11.0–25.5, and 30.4–81.7, respectively, much higher than those of porous materials such as activated carbon, OMCS, Zeolite A, UiO-66, and SBA-15. Moreover, N-OMCS-T could act as efficient and long-lived metal-free catalysts for selective oxidation of the captured H2S to sulfur under mild conditions.

Meso‐macroporous Carbons Decorated with Ample Nitrogen Sites as Bifunctional Catalysts in CO2 Catalytic Conversion and Oxygen Reduction Reaction

“…In the Raman spectra, two peaks ascribed to D and G bonds at 1344 and 1583 cm −1 were observed, respectively. The D and G bands are associated with sp 3 and sp 2 carbon materials, respectively [32–37] . From 3D‐NHPC‐1 to 3D‐NHPC‐6, the ratio of G band gradually decrease and the bands associated with 2D and S3 gradually disappear, suggesting the contents of structural defects and lattice disorders in the 3D‐NHPC‐x were increased.…”

Facile and environmentally friendly synthesis of ultramicroporous carbon spheres: A significant improvement in CVD method

“…Carbon spheres (CS) ranging in size from nanometers to micrometers have received considerable attention over the past decade due to their outstanding role in some applications such as energy storage and conversion, catalysis, gas adsorption and storage, drug and enzyme delivery, and water treatment [1][2][3]. So far, several pathways have been developed for the synthesis of CS, [4] including nanocasting with silica spheres as hard templates, [5] hydrothermal carbonization of carbohydrates [6], chemical vapour deposition (CVD) [7,8], modified Stöber synthesis [9], soft-templating methods [10][11][12], plasma [13],…”

Amine-Grafted Mesoporous Carbons as Benzocaine-Delivery Platforms

“…Their highly tunable properties, such as porosity in the range of 2–50 nm, well-developed surface area, and high thermal and chemical stability, are the base, on top of which further functionalities can be built. Up to now, OMCs and their adsorption capabilities have been applied in various fields, such as hydrogen [ 3 ] and energy [ 4 ] storage, catalysis [ 5 , 6 ], gas capture [ 7 , 8 ], water treatment [ 9 , 10 ], and drug delivery [ 11 , 12 ]. Whilst the latter application of OMCs as carriers for active pharmaceutical ingredients (APIs) is newly emerging, they are more often considered due to their confirmed biocompatibility [ 13 , 14 , 15 ].…”