Ethylene glycol as an alternative solvent approach for very efficient hydrogen production from sodium borohydride with phosphoric acid and acetic acid catalysts

Abstract

For the first time, phosphoric acid (H 3 PO 4 ) and acetic acid (CH 3 COOH) catalysts were used for efficient hydrogen (H 2 ) production from sodium borohydride (NaBH 4 ) ethylene glycolysis reaction. In this experimental study, the effects of ethylene glycol/water ratio, ethylene glycol/acid ratio, NaBH 4 concentration, acid concentration, and temperature were investigated. These ethylene glycol/water ratio experiments showed that the use of water alongside ethylene glycol negatively affects H 2 production. The hydrogen generation rate (HGR) values obtained for this ethylene glycolysis reaction with 1 M H 3 PO 4 and 1 M CH 3 COOH catalysts are 5800 and 4542 mLmin -1 , respectively. Also, the completion times of ethylene glycolysis reactions with these acids are 8 and 10 s, respectively. The n value obtained for ethylene glycolysis reactions according to the power-law kinetic model was 0.50. The activation energies obtained with H 3 PO 4 and CH 3 COOH catalysts were 24.45 kJ mol −1 and 33.23 kJ mol −1 , respectively. • H 3 PO 4 and CH 3 COOH were used for H 2 production from ethylene glycolysis of NaBH4. • HGR value obtained for the ethylene glycolysis reaction with 1 M H 3 PO 4 is 5800 mLmin -1 . • HGR value for the ethylene glycolysis reaction with 1 M CH 3 COOH is 4542 mLmin -1 . • The activation energies with H 3 PO 4 and CH 3 COOH were 24.45 kJ mol −1 and 33.23 kJ mol −1 .