Ni/H-ZSM-5 as a stable and promising catalyst for COx free H2 production by CH4 decomposition

Abstract

Catalytic decomposition of methane for CO_x free hydrogen production is carried out over Ni supported on H-ZSM-5 catalysts with different Si/Al ratios (i.e. 40, 150, 300 and 485) at 550 °C and atmospheric pressure. Methane decomposition activity of Ni/H-ZSM-5 is decreased with time on stream and finally deactivated completely. The fresh and reduced catalysts are characterized by BET-SA, XRD, FT-IR, UV-DRS, TPR, pulse chemisorption of H₂ and N₂O and some of the used catalysts are characterised by CHNS, SEM, TEM and Raman spectroscopy. Raman spectra of the used catalysts showed both ordered and disordered carbon at 1580 cm⁻¹ and 1320 cm⁻¹. The 20 wt% Ni/H-ZSM-5 (Si/Al = 150) exhibited a higher H₂ production rate over the other Ni loadings. The superior performance of 20 wt% Ni/H-ZSM-5 (Si/Al = 150) is rationalized by the physico-chemical properties of the various Ni loaded H-ZSM-5 catalysts.