Review of Researches on SCR Catalyst with Low Temperature and high Sulfur Tolerance and Theoretical Design

Yufei Zhang,X Wei

doi:10.1051/e3sconf/202021301012

Abstract

Selective catalytic reduction (SCR) of nitrogen oxides (NOx) using ammonia (NH3) is currently the main technology for flue gas denitration. However, the currently widely used commercial catalysts (such as V2O5-WO3 / TiO2, V2O5-MoO3 / TiO2, etc.) have the disadvantages of high operating temperature, narrow active temperature window, and high catalytic cost. Therefore, in recent years, researchers have devoted themselves to the development of low-cost and efficient low-temperature SCR catalytic materials. This paper summarizes the research progress of low-temperature (less than 250 °C) selective catalytic reduction of NOx by unsupported metal oxide catalysts, supported metal oxide catalysts, precious metals, and molecular sieve catalysts. Among them, manganese-based catalysts show good low-temperature selectivity and stability, and have good application prospects. Finally, the research directions of manganese low temperature SCR catalysts are prospected and theoretically designed based on the existing problems.

Highlights

Nitric oxide (NOX) refers to compounds composed of nitrogen and oxygen
According to the variation trend, we found that China has made great efforts to reduce NOX emission and achieved significant effect
For Selective catalytic reduction (SCR), SO2 serves for different roles in the high-temperature interval and low-temperature interval

Summary

Introduction

Nitric oxide (NOX) refers to compounds composed of nitrogen and oxygen. Common NOX include N2O, NO, NO2, N2O3 and N2O5. NO and NOX are common atmospheric pollutants. NOX has the following three aspects of harms, which are harms to physical health, damages of acid rains to crops, soils and forest, and atmospheric damages. 90~95% of NOX in atmosphere comes from emission of industrial factories. According to the variation trend, we found that China has made great efforts to reduce NOX emission and achieved significant effect. How to decrease NOX emission from industrial factors is still the key research hotspot in future. The supported SCR catalysts which use transition metallic oxide as the activity center are the key development objects in future

Conclusions and reviews of researches on low-temperature SCR catalysts

Mn-based catalyst

Introduction to the MnO2 structure

Research conclusions on sulfur resistance improvement

Findings

Conclusions