Effect of B-Site Element on the Structure and Catalytic Performance for Toluene of the 3DOM CeBO₃ Catalyst

Abstract

A series of 3DOM cerium-based perovskite catalysts with different B-site elements were prepared by the colloidal crystal template method and excess impregnation method with Cr, Ni, and Mn as the B-site elements. The physical and chemical properties of the catalysts were investigated by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), hydrogen temperature-programmed reduction (H2-TPR), and oxygen temperature-programmed desorption (O2-TPD) characterization techniques. The results showed that the catalyst with Mn as the B-site element had a high-quality macropore structure (pore size 200–250 nm), large specific surface area (45.26 m2/g), and abundant surface adsorbed oxygen content (Oads/Olatt = 0.46). The addition of manganese enhanced the low-temperature reducibility, and the main reduction peak was below 400 °C. The O2-TPD results showed that 3DOM CeMnO3 expressed the highest adsorption oxygen content. The 3DOM CeMnO3 possessed the best catalytic performance with T 50% = 102 °C and T 90% = 203 °C during the catalytic oxidation of toluene. Intermediate product study hinted that toluene was first converted into benzoic acid and benzaldehyde and then further degraded into small molecules. The catalyst with the best activity also exhibited good stability, and toluene degradation rate remained above 85% at 200°C for more than 20 h of continuous experiments.

Lattice Oxygen Activation Triggered by Ultrasonic Shock Significantly Improves NO Selective Catalytic Reduction

“…First, oxygen temperature-programmed desorption (O 2 -TPD) analysis was applied to explore the strength of the Fe–O bond and the mobility of oxygen species. As shown in Figure a, no obvious O 2 desorption at temperature below 300 °C was detected for both samples, revealing molecular oxygen adsorption on catalyst surface was hardly promoted by ultrasonic treatment . Notably, a drastic difference in desorption signal of O 2 was observed when the temperature exceeded 300 °C.…”

Weakening Mn–O Bond Strength in Mn-Based Perovskite Catalysts to Enhance Propane Catalytic Combustion

“…Therefore, it is of great value and significance to develop efficient VOC emission control methods and technology. Catalytic combustion (oxidation) has been widely regarded as one of the most promising ways to eliminate VOC emissions due to its low cost and high efficiency. , The core of this technology lies in the development of catalysts that convert harmful VOCs into harmless CO 2 and H 2 O, which can exhibit remarkable activity at low temperatures and exceptional thermal stability at high temperatures. , Although noble metal-based ( e.g. , Pt and Pd) catalysts have high catalytic activity for VOC oxidation, − the high cost poses a significant barrier to widespread implementation, which has prompted researchers to focus on developing low-cost transition metal oxide catalysts. − …”