High Dispersed Pd, Pt Supported on La, Ce-Alumina for Excellent Low Temperature Toluene Oxidation: Effect of Calcination Temperature and Ascorbic Acid Reduction

Seeking highly dispersed noble metals catalysts with varied valence, together with oxygen species and Lewis acid regulation are an important way to meet high efficiency toluene oxidation. Herein, the catalyst of 1 wt.% Pt and 1 wt.% Pd loaded on Al₂O₃ modified with La, Ce (PtPd/LCA), is synthesized through the adjustment of different calcination temperature from 250 to 550 °C under ascorbic acid reduction. Their redox, surface oxygen species, surface species acid properties and reaction mechanism were systematically characterized by H₂-TPR, O₂-TPD, XPS, pyridine-IR and in-situ DRIFTS. PtPd/LCA-250 totally eliminats toluene at 175 °C under 60,000 mL⁻¹ g⁻¹ h⁻¹, together with superior water resistance and stable performance. Lower calcinated temperature and reduction of ascorbic acid, which leading to the proper co-existence of Pd and PdO, together with the abundant surface chemically adsorbed oxygen species and Lewis acid sites, is responsible for better catalytic activity. The catalyst could be a step forward in designing efficient and facile technologies for abatement of VOCs. Graphical Abstract: [Figure not available: see fulltext.].