V-Sb Composite Oxide SCR Catalyst for Low-Temperature NOx Removal
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Solution Overview
Problem
Current SCR catalysts, particularly those based on vanadium and antimony, face challenges in achieving excellent NOx removal efficiency across a broad temperature range, especially at low temperatures below 300°C, in both mobile and stationary exhaust gas emission applications.
Innovation Solution
A catalyst composition featuring a rutile-type composite oxide of vanadium and antimony supported on TiO2, with specific XRD diffraction peak characteristics and calcination temperatures, is developed to enhance NOx reduction efficiency. This composition includes optional oxides of silicon, vanadium, and antimony, and is prepared through a process involving mixing, drying, and calcination steps to optimize the catalyst's structure and activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional V/Sb catalysts are used, then SCR performance is improved, but NOx removal efficiency at low temperatures below 300°C is insufficient
Solution Approach 1:
The patent changes the chemical composition parameters by introducing a specific composite oxide containing vanadium (V), antimony (Sb), and titanium (Ti) in defined ratios, along with potassium (K) and aluminum (Al) promoters. This compositional parameter change enables the catalyst to achieve high NOx removal efficiency at low temperatures below 300°C while maintaining reliable SCR performance across a broad temperature range.
Solution Approach 2:
The patent employs a composite material system consisting of a multi-element oxide catalyst (V-Sb-Ti-K-Al-O) supported on TiO2. This composite structure combines the catalytic activity of vanadium with the promotional effects of antimony, titanium, potassium, and aluminum, creating a synergistic effect that significantly improves NOx removal efficiency at low temperatures while maintaining broad temperature range performance.
2Productivity
If catalyst composition is optimized for high NOx removal, then SCR activity improves, but catalyst structure complexity increases
Solution Approach 1:
The patent optimizes the compositional parameters by specifying precise weight percentages for each element (V: 0.1-5%, Sb: 0.1-5%, Ti: 1-50%, K: 0.1-5%, Al: 0.1-5%) and defines the molar ratio relationships between elements. This parameter optimization achieves high NOx removal efficiency while maintaining a manageable catalyst structure that can be synthesized through controlled calcination processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The catalyst composition demonstrates improved NOx conversion rates, particularly at higher calcination temperatures, significantly enhancing the selective catalytic reduction of nitrogen oxides in exhaust gases from engines and power plants, outperforming traditional catalysts in SCR activity tests.
Implementation Method 1
a process comprising adding ammonia as a reducing agent to catalytically reduce NOx selectively to N2
Implementation Method 2
calcining at 500-700°C for 1-5 hours to obtain the composite oxide
Data Source
AI summary
A catalyst composition comprising—a support comprising TiO2,—a composite oxide containing vanadium and antimony, which has a rutile-type structure different from VSbO4 and V0.92Sb0.92O4 as determined by X-ray diffraction (XRD) analysis with CuKα radiation, and—optionally, one or more selected from the group consisting of oxides of silicon, oxides of vanadium and oxides of antimony, for selective catalytic reduction of nitrogen oxides; to a process for preparing the catalyst composition, to the catalyst composition obtained/obtainable by the process and to use of the same for selective catalytic reduction of nitrogen oxides.