Study on the Performance of Copper‐Manganese Composite Oxide Catalysts for Toluene

Abstract

Copper-manganese (CuMn) composite oxide catalysts were prepared for the catalytic combustion of a common volatile organic compound, namely toluene. The structural properties of the catalysts were analysed by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) theory, X-ray photoelectron spectroscopy (XPS) and hydrogen temperature-programmed reduction (H 2 -TPR). The catalytic stability was examined after 100 h. It was found that Cu 1 Mn 1 exhibited the highest catalytic ability when the molar ratio of Cu : Mn was 1 : 1. The removal of toluene reached 90 % at a temperature below 229°C. It was speculated that the Cu 1.5 Mn 1.5 O 4 spinel structure and CuO were formed in the catalyst. The catalyst surface area was not the main factor affecting the catalytic activity. The catalysts displayed good stability and maintained high catalytic activity for a long time. Notably, fresh catalysts contained high amounts of high-valent Mn 4 + and Cu 2 + cations, which played important roles in the catalytic combustion of toluene. The cations initiated the redox process and led to the conversion of toluene to CO 2 and H 2 O. The reduced lattice oxygen supplied from air was transformed into surface oxygen on the catalyst. The catalytic combustion of toluene in the presence of CuMn composite oxide catalysts followed the Mars-van Krevelen mechanism.

Study on catalytic degradation of toluene by copper manganese composite oxide

“…The stability of the catalyst toward toluene oxidation is an essential factor. The stability (continuous reaction for 70 h) of Cu 2 Mn 1 , Cu 2 Mn 1 , and Cu 2 Mn 1, prepared at calcination temperature of 500°C are shown in Figure 12 26 . At space velocity 12,000 h −1 , reaction temperature of 260°C, and toluene concentration of 500 mg/m 3 , the catalytic performance of the catalysts did not change and remained stable for a long reaction time.…”

“…The stability (continuous reaction for 70 h) of Cu 2 Mn 1 , Cu 2 Mn 1 , and Cu 2 Mn 1, prepared at calcination temperature of 500 C are shown in Figure 12. 26 At space velocity 12,000 h À1 , reaction temperature of 260 C, and toluene concentration of 500 mg/m 3 , the catalytic performance of the catalysts did not change and remained stable for a long reaction time. Thus, it can be concluded that the Cu 2 Mn 1 catalyst not only has high catalytic performance, but also has good stability, which is suitable for the catalytic reaction of toluene (Figure 13).…”

Rare Earth Dopants Enhance Thermocatalytic Activity of Manganese Oxides on Corrugated Silica Carriers for Formaldehyde Degradation

“…Volatile organic compounds (VOCs) with a great toxicity to human health mainly come from the industrial exhaust gas during petrochemical, pharmaceutical, printing and burning processes. [1,2] Formaldehyde (HCHO), one of the representative VOC pollutants, tends to cause neurological dementia, [3] lung injury, [4] myeloid leukemia, [5] and teratogenicity. [6] The efficient detection and elimination of HCHO molecules remains a great challenge.…”

Rod‐Like MnOx Catalyst Derived from Mn‐MOF‐74 for Chlorobenzene Oxidation at Low Temperature

“…Considering that industrial CVOCs exist in the form of low concentration and high throughput, catalytic oxidation has become one of the most feasible, economical and reliable method due to its high efficiency and selectivity at low temperature. Generally, catalytic oxidation is closely related to catalysts, and finding highly efficient catalysts is the main direction of efforts [6–9] . During the past decades, the catalysts used for catalytic oxidation of CB could be mainly divided into three categories, namely noble metals, metal oxides and perovskite‐type catalysts [10–12] .…”

“…Generally, catalytic oxidation is closely related to catalysts, and finding highly efficient catalysts is the main direction of efforts. [6][7][8][9] During the past decades, the catalysts used for catalytic oxidation of CB could be mainly divided into three categories, namely noble metals, metal oxides and perovskite-type catalysts. [10][11][12] However, the noble metal catalysts are expensive and susceptible to chlorine poisoning, and perovskite-type catalysts have poor porosity and undesirable redox properties, resulting in unsatisfactory activity at low temperature, all of which limit their practical application in industry.…”