Sustainable conversion of biodiesel-waste glycerol to acrolein over Pd-modified mesoporous catalysts

Abstract

The sustainable biodiesel industry relies on converting biorefinery by-product glycerol into valuable chemicals. A wet-impregnated Pd/SBA-15 catalyst for the selective dehydration of glycerol to acrolein is presented in this study. Various analytical techniques were used to confirm the catalysts' physicochemical characteristics, including X-ray diffraction, pulse CO chemisorption, BET surface area, TEM, and H2-TPR. The results demonstrate that Pd nanoparticles were incorporated into SBA-15 in a homogeneous dispersion. Due to its high surface area and sufficient Bronsted acidic sites, the Pd/SBA-15 catalyst can enhance selectivity for acrolein and reduce poisoning susceptibility. A fixed-bed reactor operating in the vapour phase was used to verify the efficiency of the prepared acid catalysts for selectively converting glycerol to acrolein. It was discovered that 2 wt% Pd nanoparticles supported on the SBA-15 catalyst exhibit 89.6% glycerol conversion and 64.2% acrolein selectivity at 320 °C. It was found that the acidic sites (Lewis & Brønsted), homogenous Pd nanoparticle dispersion, and the support (i.e., SBA-15) conferred its superior catalytic activity. Various reaction parameters, including temperature, TOF, Pd loadings, and weight hour space velocity, also affect catalytic activity.

Keywords

• Biodiesel-waste
• Biorenewable glycerol
• Dehydration
• Pd nanoparticles
• SBA-15 support
• Acrolein