Wang N, Zhou X, Yu X, Song Y, Ullah S, Nie X, Wang N, Zhang L. Preparation of Solid Superacid SO
42-/ZrO
2 and SO
42-/ZrO
2-M
xO
y (M=Ce, Co, Mn, and Zn) and Its Application in Toluene Nitration.
ACS OMEGA 2024;
9:12037-12045. [PMID:
38496941 PMCID:
PMC10938450 DOI:
10.1021/acsomega.3c09663]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/05/2024] [Accepted: 02/09/2024] [Indexed: 03/19/2024]
Abstract
The nitration reaction of aromatic compounds is one of the extensively studied chemical reactions that result in the manufacturing of various industrial products applied in pharmaceuticals, dyes, perfumes, and explosives. A series of modified sulfated zirconia (SZ) catalysts SO42-/ZrO2-MxOy (M=Ce, Co, Mn, Zn, and M/SZ) doped with different metal elements by a coprecipitation method were investigated in the toluene nitration reaction. Various characterization techniques (X-ray diffraction, Brunauer-Emmett-Teller, thermogravimetric analysis, X-ray photoelectron spectroscopy, and temperature-programmed desorption of ammonia) indicated that doping metal elements in SZ led to excellent catalytic properties, increasing the specific surface area of the catalyst and facilitating the formation of a stable tetragonal zirconia phase. Doping zinc and cobalt in SZ enhanced the acidity of the catalyst and formed stronger acidic sites, promoting the generation of nitronium ions and providing more active sites for the toluene nitration reaction. Additionally, it reduced the loss of sulfate ions in the catalytic system that helped in improving the stability of the catalyst. Under the same conditions, the catalytic activity of toluene nitration reaction demonstrated the following order: Zn/SZ > Ce/SZ > Co/SZ > Mn/SZ > SZ, with the zinc-doped SZ catalyst exhibiting the best catalytic performance, achieving a toluene conversion rate of 78.58% and a para/ortho nitrotoluene ratio of 0.67.
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