Pt Nanoparticles Embedded in KOH-Activated Soybean Straw as an Efficient Catalyst toward Benzene Oxidation

As an abundant and renewable biological resource, straw has been attracting wide attention due to its distinctive tubular structure and property. Herein, soybean straw was pretreated by KOH and was used as a support for Pt nanoparticles (NPs) to realize efficient benzene combustion. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images of straw-derived samples illustrated the channel wall with open macropores and uniform distribution of Pt NPs in the straw skeleton. As a result, the temperature for 90% benzene conversion (T90%) by Pt/KAC-3 (Pt/KAC-n, where n represents the mass ratio of straw to KOH that was varied between 1:1, 1:2, and 1:3) was determined to be 179 °C under a space velocity (SV) of 120 000 mL/(g·h). Additionally, thermal stability was enhanced to nearly 96 h. This performance is predominantly attributed to its inherent channel structure, which has open and accessible pores, resulting in a uniform distribution of Pt NPs. Such structure enables the rapid transfer of benzene molecules between channels and ensures the accessibility of Pt NPs. Furthermore, the diffusion properties were confirmed by Fick’s second law. This study demonstrated a design of more efficient catalysts while using a renewable and abundant biomaterial.