Platinum Oxide on Tin Oxide Catalyst for High-Temperature Methane Oxidation
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Solution Overview
Problem
Methane oxidation catalysts supported on tin oxide experience a significant decrease in catalytic performance when exposed to high temperatures during engine misfires, leading to ineffective methane removal from exhaust gases.
Innovation Solution
A methane oxidation catalyst with platinum oxide supported on a tin oxide carrier, characterized by a specific XANES spectrum intensity and EXAFS ratio, maintains methane oxidation activity by suppressing platinum particle aggregation and controlling the oxidation state of platinum, ensuring activity even at high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If platinum is supported on tin oxide to oxidize methane at low temperature, then methane oxidation activity is improved, but catalytic performance significantly decreases when exposed to high temperature during misfire
Solution Approach 1:
The patent changes the oxidation state of platinum from metallic (Pt0) to oxidized (Pt2+ or Pt4+) form. This parameter change allows the catalyst to maintain stable performance at high temperatures during misfire while still achieving effective methane oxidation at low temperatures, resolving the contradiction between low-temperature activity and high-temperature stability
Solution Approach 2:
The patent creates a composite catalyst system combining platinum oxide with tin oxide support. This composite structure provides both the low-temperature oxidation activity of platinum and the high-temperature stability of the tin oxide support, preventing the performance degradation that occurs with pure platinum-supported catalysts during misfire events
2Productivity
If platinum particles are used for methane oxidation, then catalytic activity is improved, but platinum particle aggregation occurs at high temperature leading to activity loss
Solution Approach 1:
The patent performs preliminary oxidation of platinum particles before they are deployed as catalyst. By pre-forming platinum oxide species, the structure is stabilized in advance to prevent aggregation during high-temperature misfire events, thereby maintaining both productivity and compositional stability
Solution Approach 2:
The tin oxide support acts as an intermediary between platinum particles and the high-temperature environment. It provides a stable surface that prevents direct platinum particle aggregation while still allowing methane oxidation to proceed efficiently, thus maintaining both activity and dispersion stability
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 maintains methane oxidation activity at levels comparable to normal cycles, even after exposure to high temperatures, effectively oxidizing methane in exhaust gases during misfires.
Implementation Method 1
a methane oxidation catalyst in which a platinum oxide is supported on a tin oxide carrier
Implementation Method 2
oxidizing unburnt methane contained in exhaust gas
Implementation Method 3
the intensity of an absorption peak obtained in the range of 11555 to 11570 eV in the L3 edge X-ray absorption near-edge structure (XANES) spectrum of the platinum atom
Implementation Method 4
the radial distribution function obtained by Fourier transformation of the L3 edge extended X-ray absorption fine structure (EXAFS) spectrum
Data Source
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AI summary
[Problem to be Solved] An improvement is made in an oxidation catalyst in which platinum is supported on a tin oxide, and provided is a novel oxidation catalyst which can maintain methane oxidation activity even after the catalyst is exposed to a high temperature. [Means to Solve the Problem] A methane oxidation catalyst in which a platinum oxide is supported on a tin oxide carrier, wherein the intensity of an absorption peak obtained in the range of 11555 to 11570 eV in the L3 edge X-ray absorption near edge structure (XANES) spectrum of a platinum atom is 1.4 times or more the intensity of an absorption peak measured using a standard platinum foil.