Mn-Doped material synthesized from red mud and rice husk ash as a highly active catalyst for the oxidation of carbon monoxide and p-xylene. (17th November 2020)

• Record Type: Journal Article
• Authors: Van Nguyen, Thi Thuy; Nguyen, Tri; Nguyen, Phung Anh; Pham, Thi Thuy Phuong; Mai, Thanh Phong; Truong, Quang Duc; Ha, Huynh Ky Phuong
• Is Part Of: New journal of chemistry. Volume 44:Number 46(2020)
• Page Start: 20241
• Page End: 20252
• Publication Date: 2020-11-17
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d0nj03947k
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Red muad and rice husk ash were treated without neutralization by acid to produce a support material (RR). Abstract : Red muad and rice husk ash were treated without neutralization by acid to produce a support material (RR). A series of Mn-doped RRs were prepared by an impregnation method for the catalytic oxidation of CO and/or p -xylene. Various techniques such as X-ray powder diffraction (XRD), Brunauer–Emmett–Teller (BET) nitrogen physisorption measurements, hydrogen temperature-programmed reduction (H2 -TPR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) were used to characterize the catalysts. XRD and XPS analysis confirmed the existence of Mn2 O3 in the MnRR1 samples. The addition of Mn2 O3 into RR led to a decrease in the surface area of RR from 25.6 m 2 g −1 to 19.0–24.8 m 2 g −1, pore volume from 0.018 cm 3 g −1 to 0.013–0.017 cm 3 g −1, and average pore diameter from 20.4 Å to 18.8–20.3 Å, suggesting that Mn2 O3 can be deposited inside the pores of the material. Among these catalyst samples, 3MnRR1 prepared by 3.0 wt% Mn doped into RR showed the best performance for CO or p -xylene deep oxidation, achieving CO conversion of 100% at approximately 280 °C and p -xylene conversion of 93% at 400 °C. Meanwhile, the conversion of CO and p -xylene in a mixture was found to be much lower than that in a pure substance. An increase in the moisture content was found to lead to lower CO and p -xylene conversion. The obtained catalyst pellet used kaolin as a binder and showed a mechanical strength of 12.4 MPa and a low weight attrition rate of 1.8%. The result indicated that a pellet catalyst had a slightly lower catalytic activity than that in the powder catalyst for CO/ p -xylene conversion at the investigated temperatures, the conversions of CO were approximately 98% at 320 °C, and the conversion of p -xylene was 83.8% at 450 °C, and remained almost stable during 50 h of testing. These results confirm that MnRR2 catalytic pellets are promising for industrial catalyst applications.