Hydrolytic Cleavage Of Ammonia Borane Complex For Hydrogen Production

Ammonia-borane (AB) complex is a chemical hydride that is stable in air and water, and contains very high hydrogen content (19.6 wt%). AB is a promising material as a hydrogen carrier especially for power generation utilizing proton exchange membrane fuel cells (PEMFC). Release of hydrogen in the AB complex can occur by either thermolysis or hydrolysis. Thermolysis of AB generates, in addition to hydrogen, species such as borazine, monomeric aminoborane, and diborane, among others that have adverse effect on the PEMFC operation. In this paper, we present a new process for generating hydrogen via near room temperature hydrolysis of AB complex using small amounts of several platinum group metal catalysts. The kinetics of the AB hydrolysis in the presence of K2Cl6Pt catalyst was studied using in situ 11B-NMR spectroscopy. The GC/MS analysis of the product gas showed that the amount of ammonia detected in the reactor effluent was significantly less when phosphoric acid was used as a sequestering agent. Copyright © (2006) by AFHYPAC