Decomposition of formic acid over silica encapsulated and amine functionalised gold nanoparticles

作者：Mielby Jerrik; Kunov Kruse Andreas Jonas; Kegnaes Soren^*

来源：Journal of Catalysis, 2017, 345: 149-156.

DOI：10.1016/j.jcat.2016.11.020

• Encapsulation
• Gold nanoparticles
• Heterogeneous catalysis
• Silica
• Formic acid
• Hydrogen
• ATR-FTIR
• Kinetic isotope effect

Formic acid has recently attracted considerable attention as a safe and convenient source of hydrogen for sustainable chemical synthesis and renewable energy storage. Here, we show that silica encapsulated and amine functionalised gold nanoparticles are highly active catalysts for the production of hydrogen by vapour phase decomposition of formic acid. The core-shell catalysts are prepared in a reverse micelle system that makes it possible to control the size of the Au nanoparticles and the thickness of the SiO2 shells, which has a large impact on the catalytic activity. The smallest gold nanoparticles are 2.2 +/- 0.3 nm in diameter and have a turnover frequency (TOF) of up to 958 h(-1) at a temperature of 130 degrees C. Based on detailed in situ ATR-FTIR studies and results from kinetic isotope labelling experiments we propose that the active site is a low-coordinated and amine functionalised Au atom, while H-assisted formate decomposition into CO2 and H-2 is the rate limiting step.

• 出版日期2017-1