Structured Macroporous SiC-LaNiO3 Catalysts for Hydrogen Production via Visible-Light Glycerol Photoreforming

Abstract

Robust supports functionalized with active catalytic phases present a promising route to enhance photocatalytic hydrogen production. Progress in hydrogen generation strongly depends on the design of structured catalysts with tailored architectures and active interfaces. This study presents macroporous silicon carbide (SiC) structures functionalized with LaNiO₃ perovskite as structured catalysts for glycerol photoreforming under visible light. SiC foams were fabricated via the replica method using polymeric templates and sintered at 1000°C, with a vitreous frit residue serving as a flux agent to enable more energy-efficient processing. LaNiO₃ was synthesized by a sol–gel route. The materials were characterized by zeta potential, x-ray diffraction, scanning electron microscopy (SEM)/energy-dispersive x-ray spectroscopy (EDS), diffuse reflectance spectroscopy, and surface area measurements. Photocatalytic tests were performed under visible irradiation in an in-house quartz reactor, and hydrogen evolution was monitored using an Arduino-based acquisition system coupled to an MQ-8 sensor. Glycerol, a common byproduct of biodiesel production, was used as a sacrificial agent, highlighting the potential of waste-derived feedstocks for sustainable solar fuel production. Under the tested conditions, the SiC-LaNiO₃ structured catalyst produced approximately 90 µmol g⁻¹ of H₂ in 60 min, outperforming bare SiC (≈57 µmol g⁻¹). The improved performance is associated with enhanced visible-light absorption, lower bandgap, increased accessible surface area, and the intrinsic robustness of the structured SiC support.