Mechanism and Performance of the SCR of NO with NH3 over Sulfated Sintered Ore Catalyst

Abstract

A sulfated sintered ore catalyst (SSOC) was prepared to improve the denitration performance of the sintered ore catalyst (SOC). The catalysts were characterized by X-ray Fluorescence Spectrometry (XRF), Brunauer–Emmett–Teller (BET) analyzer, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance infrared spectroscopy (DRIFTS) to understand the NH3-selective catalytic reduction (SCR) reaction mechanism. Moreover, the denitration performance and stability of SSOC were also investigated. The experimental results indicated that there were more Brønsted acid sites at the surface of SSOC after the treatment by sulfuric acid, which lead to the enhancement of the adsorption capacity of NH3 and NO. Meanwhile, Lewis acid sites were also observed at the SSOC surface. The reaction between −NH2, NH 4 + and NO (E-R mechanism) and the reaction of the coordinated ammonia with the adsorbed NO2 (L-H mechanism) were attributed to NOx reduction. The maximum denitration efficiency over the SSOC, which was about 92%, occurred at 300 °C, with a 1.0 NH3/NO ratio, and 5000 h−1 gas hourly space velocity (GHSV).

Low-Temperature Selective Catalytic Reduction of NO with NH3 over Natural Iron Ore Catalyst

“…When the SO2 feed was stopped after 400 min, the NO conversion was restored to some extent. Compared with the previous reports [41,42], our experiments exhibited that the iron ore sample had better tolerance to SO2 at 200 °C in one hour of added SO2. However, after this time, substantial deactivation occurred due to the formation of sulfates on the surface of the catalyst, which resulted in a sharp decrease in NO conversion.…”

Emissions Control Catalysis

“…Han J. and co-workers [22] investigated the enhanced deNO x performance and stability of sulfated sintered ore catalysts (SSOC) during the selective catalytic reduction of NO x with NH 3 . The maximum deNOx efficiency found was about 92% at 300 • C, NH 3 /NO = 1 and 5000 h −1 gas hourly space velocity (GHSV).…”

“…The review of Smirniotis P. and co-workers [18] concerns the selective catalytic reduction of NO x with NH 3 (NH 3 -SCR of NO x ) focusing to low temperature applications that is a highly desirable perspective, and finally the review of Bogaerts A. and co-workers [19] covering a hot recent trend in emissions control implicating cyclic economy strategies, that is the conversion and utilization of CO 2 for the production of value-added chemicals. On the other hand, a major part of contributions (9/21) concerns original research on nitrogen oxides reduction processes [20][21][22][23][24][25][26][27][28], reflecting the fact that this topic still remains hot among the targets of environmental catalysis. Five out of 21 studies concern CO and hydrocarbons oxidation processes [29][30][31][32][33] while the remained 4/21 concern CO 2 capture/recycling processes under the view of cyclic economy [34][35][36][37].…”

Effect of Molybdenum on the Activity Temperature Enlarging of Mn-Based Catalyst for Mercury Oxidation

“…The Brunauer-Emmett-Teller (BET) surface area and pore size distribution were controlled by ASAP 2020 (Micromeritics, America) [33][34][35]. X-ray photoelectron spectroscopy (XPS) and XRD of the three catalysts were determined by VG Multilab 2000 X-ray Photoelectron Spectroscopy and X'pert PRO X-ray powder diffraction (PANalytical, Holland) [36][37][38], respectively. Sirion 200 scanning electron microscope (FEI, Holland) was used to characterize the SEM of the three catalysts [39].…”