Local Microenvironment Modulation of Pt0/Pt2+ Nano-clusters Inducing Synchronous Mass Transfer Effect to Boost Catalytic Ozonation

Rational catalyst structure design is expected to solve the low O3 utilization and poor molecular mass transfer efficiency in heterogeneous catalytic ozonation (HCO). Herein, Pt/CMK-3 catalyst with confined space to enhance mass transfer was synthesized and employed for CH3SH removal. Unlike fully free diffusion in 0~2.0wt.% Pt/CMK-3 and bulk phase diffusion in 10.0wt.% Pt/CMK-3, removal efficiency of 5.0wt.% Pt/CMK-3 was significantly improved to 97.0%, which was attributed to the effective interfacial diffusion of O3 and CH3SH through local microenvironment modulation of Pt0/Pt2+ nanoclusters (NCs) inducing synchronous mass transfer. Experimental and DFT calculations confirmed the strong electronic interactions between O3 and Pt0 facilitated charge redistribution and preferential O3 activation. AIMD simulation demonstrated that the synchronous difference in mean-square displacements (MSD) and diffusion coefficient (Dc) of CH3SH (Dc=0.022) and O3 (Dc=0.0046) in the confined Pt/CMK-3 system could facilitate CH3SH migrate to Pt2+ through interfacial diffusion. Especially, the d-orbital electrons of Pt NCs interact sequentially with p-orbital electrons of CH3SH and O3 to maintain redox of Pt0/Pt2+. This study provides novel insights on effective mass transfer and kinetic properties of gaseous reaction between oxidant and pollutant by constructing unique interfacial diffusion behaviors.