Perovskite modified catalysts with improved coke resistance for steam reforming of glycerol to renewable hydrogen fuel

<p>Catalytic steam reforming of renewable<span> feedstock to renewable energy or chemicals always goes with intense coking activities that produce carbonaceous products leading to low performance and eventual catalyst deactivation. A supported</span> metal catalyst such as Ni/Al₂O₃ is known to catalyse gasification and decomposition of biomass feedstock largely for renewable fuel production with promising results. Catalyst deactivation from high carbon deposition, agglomeration, and phase transformations resulting in rapid deactivation are some of the issues identified with the use of the catalyst. In this work, improvement on the coke resistance and catalytic properties of the Ni/Al₂O₃ catalyst is sought via the use of a thermally stable and coke-resistant perovskite La_0.75Sr_0.25Cr_0.5Mn_0.5O_3-δ (LSCM) as catalyst promoter/modifier and involving Zirconia-doped Ceria (Ce-Zr) as alternative support in steam reforming of pure and by-product glycerol. The stabilizing influence of the LSCM on the Ni catalyst has improved stability against agents of deactivation with a significant improvement of catalytic activity of Ni/Al₂O₃ in H₂ production and robust suppression of carbon deposition. Particularly, the synergy between the LSCM promoter and alternative Ce_0.75Zr_0.25O₂ support enhanced the basic and redox properties known for Ce_0.75Zr_0.25O₂ support in contrast to the weak acid centres in the γ-Al₂O₃ support which further improved nickel stability, catalyst-support interaction with a resultant high catalytic activity, and robust coke suppression as a result of enhanced oxygen mobility. There is a correlation between the product distribution, nature of coke deposited, and reforming temperature, as well as the type of support and structural modification. Hence, the integration of a robust perovskite material as a catalyst promoter and choice of support could be tailored in the design and development of robust catalyst systems to improve the performance of supported metal catalysts particularly the suppression of carbon deposition for hydrocarbon and biomass conversion to renewable fuel or chemicals.</p>