Study of the Phosphorus Deactivation Effect and Resistance of Vanadium-Based Catalysts

Abstract

We investigated the effects of phosphorus (P) on the catalytic activity and properties of V/W/Ti and V/Sb/Ce/Ti. As a result of investigating changes in the physicochemical properties of each catalyst added with P, in the V/W/Ti catalyst, P was bound to vanadium or tungsten in the form of PO 3 − (metaphosphate) and produced phosphate species. During this process, the Brønsted acid site on the catalyst surface was greatly increased, and the adsorption amount of ammonia of the catalyst was increased. However, the active site (VO) and redox properties were reduced, which inhibited the reactivity of adsorbed ammonia, and as a result, the selective catalytic reduction (SCR) efficiency was decreased. In contrast, V/Sb/Ce/Ti catalysts preferentially produce Ce−phosphate and Sb−phosphate. In this process, the production of PO 3 − and the reduction of the active site were suppressed, indicating high P resistance. In addition, with a low P content, the redox properties were increased, such that the SCR activity was improved.

The Catalytic Function of Phosphorus Enriched on the Surface of Vanadium‐based Catalysts in Selective Oxidations

“…However, the difference in acidity cannot be correlated to catalytic activity, which is only enhanced on V 2 O 5 by the PO x deposition. Similar results were found in a study, in which P added to supported V‐based reduction catalysts lead to an increased acidity and a decrease in catalytic activity [49] . Therefore, acidity is only one feature that can dictate catalytic functionality [50] …”

“…Similar results were found in a study, in which P added to supported V-based reduction catalysts lead to an increased acidity and a decrease in catalytic activity. [49] Therefore, acidity is only one feature that can dictate catalytic functionality. [50] In order to monitor any possible effects on the chemical state of the elements at the near-surface by the modification, Xray photoelectron spectroscopy (XPS) was performed.…”

Decrypting Catalytic NOX Activation and Poison Fragmentation Routes Boosted by Mono- and Bi-Dentate Surface SO32–/SO42– Modifiers under a SO2-Containing Flue Gas Stream

“…(See the Methods Section for details.) Bulk V contents of a catalyst were typically regulated to ∼2.0 wt % in previous literature dealing with low-temperature SCR ,, and thereby were also utilized in synthesizing the pristine sample. In addition, ∼1.5 wt % of Sb was verified to promote SO A 2– -modified MnV 2 O 6 with regard to Brönsted acidity, redox trait, and reluctance to SO 2 in the most proficient fashion, thus being contained in the pristine sample.…”

Effect of Various Acid Anions on Potassium Poisoning and the Mechanism of Commercial V2O5–WO3/TiO2 Catalysts for SCR of NOx

“…As displayed in Figure a, for the fresh catalyst, the bands at 3391, 3333, 3265, 3168, and 2877 cm –1 were assigned to the stretching vibration of NH 3 adsorbed on Lewis acid sites . The bands at 2965 and 2794 cm –1 were assigned to the stretching vibration of NH 4 + on Brønsted acid sites. , The bands at 1604 and 1669 cm –1 were assigned to the asymmetric deformation vibration of NH 3 adsorbed on Lewis , and Brønsted acid sites, respectively. The other bands at 1300 and 1448 cm –1 were assigned to the symmetric bending vibration of NH 3 adsorbed on Lewis , and Brønsted acid sites, ,, respectively.…”

“…12 The bands at 2965 and 2794 cm −1 were assigned to the stretching vibration of NH 4 + on Brønsted acid sites. 26,45 The bands at 1604 and 1669 cm −1 were assigned to the asymmetric deformation vibration of NH 3 adsorbed on Lewis 35,46 and Brønsted acid sites, 47 respectively. The other bands at 1300 and 1448 cm −1 were assigned to the symmetric bending vibration of NH 3 adsorbed on Lewis 26,35 and Brønsted acid sites, 26,36,47 respectively.…”