Paper Authors

Abstract

NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract

Study of Sodium Borohydride Catalyst for Hydrogen Generation - Purdue University SURF Program

Abstract

Proton exchange membrane fuel cells (PEMFC) need pure form of hydrogen for this metal hydride seems to be one of the best storage media. Amongst hydrides, sodium borohydride, NaBH4 is desirable due to its high hydrogen storage efficiency of 10.80% and the excellent stability of its alkaline solutions. The alkaline borohydride solutions undergo hydrolysis in presence of various transition-metal catalysts to produce hydrogen. The hydrolysis product being borox it can be recycled. For the hydrolysis process of NABH4, various catalysts of Pt, Ru, Ni, Co etc., have been developed for hydrogen production from borohydride solutions and reported in recent years. However, implementation of these catalysts into the fuel cell is a challenge. A summer research project with an undergraduate was launched in developing catalyst for hydrogen generation in PEMFC fuel cell. Catalysts based on chlorides of Co, NI and Ru was developed and was directly deposited on metal foam. The resulting catalyst particles are nano- size and hence provide high catalytic activities in hydrogen generation from sodium borohydride solutions. Experiments were performed on the characterizing hydrogen generation rate as function of temperature and catalysts type. The project was carried under summer undergraduate research fellow (SURF) program.

Introduction

Proton exchange membrane fuel cells (PEMFC) are on the verge of commercialization and expected to replace the internal combustion engine in transportation as well as residential power production1. However, efficient operation of the PEMFC needs hydrogen in pure form. In view of the above, on site hydrogen production from the chemical hydrides is attractive, since the hydrogen will be purer without any fuel cell poisons. Among the hydrides, sodium borohydride, NaBH4 is desirable due to its high hydrogen storage efficiency of 10.80% and the excellent stability of its alkaline solutions. Schlesinger and Brown2 disclosed a method of preparing alkali metal borohydrides and they noted that sodium borohydride was highly soluble in water, was stable in solution up to 400oC, and could be used to reduce metal salts to their metallic form, such as the reduction of nickel sulfate to nickel boride, Ni2B. Schlesinger et al.3 have reported that the alkaline borohydride solutions undergo hydrolysis in presence of various transition-metal catalysts to produce hydrogen. Sodium borohydride reacts with water according to the following reaction: NaBH4 + 2H2O NaBO2 + 4H2, alternatively, in an alkaline borohydride solution as: BH4- + 2H2O 4H2 + BO2-. Schlesinger and Brown realized that the formation of the metaborate ion (BH4-) made the 1

hydrolyzing solution basic and quickly slowed the reaction; however, they found that the use of metal salts acted as catalytic accelerators for the hydrolysis reaction. Mn(II)Cl2, Fe(II)Cl2,

• Citation

• Format
  • APA
  • APA - LaTeX bibitem
  • MLA
  • MLA - LaTeX bibitem
  • Bibtex
  • EndNote - RIS

Walter, J., & Montgomery, D., & Revankar, S. (2006, June), Study Of Sodium Borohydride Catalyst For Hydrogen Generation Purdue University Surf Program Paper presented at 2006 Annual Conference & Exposition, Chicago, Illinois. 10.18260/1-2--202