Synthesis of SBA-15/carbon composite with an ink-bottle-like pore structure by a novel pulse CVD technique

Abstract

A novel and easy post modification method, pulse chemical vapor deposition (pulse CVD), was developed to tailor the pore-opening of SBA-15 while largely keeping its surface area and pore volume. By using acetylene as carbon precursor and nitrogen as carrier gas, the poremouth of SBA-15 was effectively reduced from 8.1 nm to 5.1 nm within 5 min while maintaining the pore body at 8.1 nm. This ink-bottle-structured SBA-15/carbon composite only losses 12% BET specific surface area and 16% total pore volume, respectively. The SBA-15/carbon composite is highly hexagonally ordered and has similar particle morphology as the original SBA-15. The effect of three pore modification factors-the number of cycles of pulse CVD, the ratio of acetylene/nitrogen and the feeding time of carbon precursor, on the final pore structure of the SBA-15/carbon composite is also studied.

Carbon Overcoating of Supported Metal Catalysts for Improved Hydrothermal Stability

“…The deposition of carbon on oxide supports has been noted by other researchers when starting with aqueous solutions of sugars, − for use in photocatalysis or lithium ion batteries. However, our approach, which involves the controlled pyrolysis of sugar, is much simpler than the previously reported sugar and nonsugar methods used in carbon coating of oxides. − In this work, we describe an unexpected benefit of the carbon coating on the stability of Pd nanoparticles under aqueous conditions. The support used to demonstrate Pd stability is a commercial silica obtained from Sigma-Aldrich.…”

Functionalization of mesostructured silica–carbon composites

“…Several synthesis strategies have been reported for coating silica mesopores with a carbon layer. Thus, Zhang et al [11] and He et al [12] reported modifying the size of the pore entrances of SBA-15 by depositing a carbon layer using a chemical vapor deposition technique. The usual procedure for preparing silica-carbon composites consists in attaching organic moieties to the silica surface followed by a carbonization step [13][14][15].…”