Supported silver catalyst for reducing soot particle burning temperature and preparation method

A technology of combustion temperature and supported silver, which is applied in the field of supported silver catalysts and preparations, and can solve problems such as high price, pollution, and metering fluctuations

Inactive Publication Date: 2013-07-24
XIAMEN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although noble metal catalysts have good soot catalytic oxidation activity (including four-way catalytic activity), precious metal resources are scarce and expensive, so the practical application of this type of catalyst is severely restricted by manufacturing costs
Another type of transition metal composite oxide-type catalyst that utilizes the oxidizing gas NO present in diesel engine exhaust x As a mass transfer aid to promote the catalytic oxidation of soot, but in practical applications, the frequent fluctuations in the measurement of each component of the tail gas will lead to residual NO x polluting the environment

Method used

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  • Supported silver catalyst for reducing soot particle burning temperature and preparation method
  • Supported silver catalyst for reducing soot particle burning temperature and preparation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Weigh 100ml of 0.1M cerium nitrate solution, add 0.21g of surfactant polyvinyl alcohol (5%wt), stir evenly, add 0.1M ammonium carbonate aqueous solution to the solution, stir for 0.5h, put it into water Heat at 120° C. for 12 hours in a hot kettle, cool to room temperature, and centrifuge and wash to obtain a ceria precursor. The precursor was dried at 110°C overnight and then calcined at 500°C for 5 hours to obtain the carrier ceria. SEM results (see figure 2 ) shows that the CeO 2 The particles are spherical particles with uniform size, and the average particle diameter is about 100nm.

[0027] Weigh 0.25g of silver nitrate, dissolve it to form a solution, then add isovaleric acid (the molar ratio of isovaleric acid to silver nitrate is 3), and stir evenly. Add 1 gram of ceria to the solution, heat and stir the resulting solution at 100°C until it is evaporated to dryness, dry the obtained solid at 110°C for one night, and then calcinate at 500°C for 7 hours to ob...

Embodiment 2

[0030] The preparation method of carrier ceria is the same as that in Example 1. Weigh 0.03g of silver nitrate, dissolve it to form a solution, then add propionic acid (the molar ratio of propionic acid to silver nitrate is 1), and stir well. Add 1 gram of ceria to the solution, heat and stir the resulting solution at 100°C until it evaporates to dryness, dry the resulting solid at 110°C overnight and then roast it at 500°C for 5 hours to obtain 1%Ag / CeO 2 catalyst.

[0031] Test the combustion situation of soot particle by the same method of implementation example 1, under this catalyst, T 10 , T 50 and T 90 The temperatures were 426°C, 551°C and 661°C, respectively.

Embodiment 3

[0033] The preparation method of carrier ceria is the same as that in Example 1. Weigh 0.125g of silver nitrate, dissolve it to form a solution, then add n-butyric acid (the molar ratio of n-butyric acid to silver nitrate is 2), and stir evenly. Add 1 gram of ceria to the solution, heat and stir the resulting solution at 100°C until it evaporates to dryness, dry the resulting solid at 110°C overnight and then roast at 500°C for 6 hours to obtain 4%Ag / CeO 2 catalyst.

[0034] Test the combustion situation of soot particle by the same method of implementation example 1, under this catalyst, T 10 , T 50 and T 90 The temperatures were 363°C, 509°C and 592°C, respectively.

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Abstract

The invention discloses a supported silver catalyst for reducing soot particle burning temperature and a preparation method, relating to catalysts. The catalyst comprises an active component and a carrier, wherein the active component is silver; the carrier is cerium dioxide or cerium-based composite oxide; the supported amount of silver is 1-20% of the weight of the carrier; and the cerium-based composite oxide has the general formula of Ce1-xMxOy, and M is rare-earth metal. The carrier is prepared by adding a surfactant as a template into a cerium-based solution through a hydrothermal precipitation method. The catalyst is prepared by introducing a complexing auxiliary agent into a water-based silver nitrate solution, evaporating to dryness and baking. The prepared catalyst has excellent oxidative activity in the process of soot burning, is capable of reducing the temperature of soot T50 from 642 DEG C to about 400 DEG C to reach the operating temperature range of a diesel engine, and reaches and exceeds various types of reported soot particle burning catalysts under the same evaluation conditions.

Description

technical field [0001] The invention relates to a catalyst, in particular to a loaded silver catalyst for reducing the combustion temperature of soot particles and a preparation method for purifying automobile exhaust. Background technique [0002] Carbon-based ultrafine particles are the main pollutants emitted by diesel engine exhaust, a large proportion (>95%) of which are particles with a particle size of less than 2.5μm (PM2.5), which are easily suspended in the air and thus breathed by humans or animals Into the body, leading to lung cancer, asthma and other diseases, seriously endangering human health. At present, in the design of diesel engines, two emission reduction strategies, internal purification and exhaust gas treatment, are often adopted. However, with the continuous tightening of emission standards, relying solely on internal purification will not only fail to meet the standards, but also limit the power and economy of motor vehicles. Therefore, it is im...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J23/66B01D53/94
Inventor 杨乐夫杨金玉蔡钒陈宁凯蔡俊修伊晓东方维平
Owner XIAMEN UNIV
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