Platinum electrode of oxygen sensor and preparation method thereof

Abstract

The invention discloses a platinum electrode of an oxygen sensor. The platinum electrode comprises a platinum electrode matrix and a protective layer attached to the matrix; the protective layer comprises a first protective layer and a second protective layer from the inside to the outside, wherein the first protective layer is formed by sintering a first coat, and the second protective layer is formed by sintering a second coat; the first coat contains yttrium oxide, stable zirconium oxide, magnesia-alumina spinel, adhesive and pore-forming agent; and the second coat contains magnesia-alumina spinel, adhesive and pore-forming agent. The porosity of the protective layer of the platinum electrode of the automobile oxygen sensor can well meet the requirement of air permeability, the platinum electrode has good thermal shock resistance, and the platinum electrode of the oxygen sensor can be effectively prevented from being poisoned, so the service life of the automobile oxygen sensor is prolonged, and the platinum electrode has great significance for the automobile manufacturing industry and environmental protection.

Description

technical field

[0001] The invention relates to a platinum electrode of an oxygen sensor and a preparation method thereof, more particularly, the invention relates to a platinum electrode of an automobile oxygen sensor and a preparation method thereof. Background technique

[0002] In the three-way control system of the automobile engine, the electronically controlled fuel supply unit, the oxygen sensor, and the three-way catalyst are the cores of the control system. In the modern engine EFI system, the most used oxygen sensor is to detect the theoretical air-fuel ratio oxygen sensor, which mainly keeps the engine working near the theoretical air-fuel ratio, so that the three-way catalyst is in the best working range. The oxygen sensor widely used at present is the concentration type zirconia oxygen sensor, which mainly adopts a tubular structure, and the zirconia tube of the sensitive element can be made by injection molding or cold isostatic pressing.

[0003] In actual u...

Examples

Embodiment 1

[0032] This example is used to illustrate the preparation of the platinum electrode of the automobile oxygen sensor provided by the present invention.

[0033] (1) Take a certain amount of Al(OH) with a particle diameter of about 1 micron 3 The solid powder is poured into an alumina burning boat and pre-fired at 250°C for 72 hours; the obtained powder is mixed with MgO powder with a particle diameter of about 1 micron in a molar ratio of 1:1 and ball milled for 10 hours, and then heated at 1350 ℃ roasting for 3 hours; after cooling, magnesium aluminum spinel powder is obtained. The prepared magnesia-aluminum spinel is pulverized, classified and screened to keep the powder of about 1 micron.

[0034] (2) 45 parts by weight of Y-ZrO 2 Micropowder (ZrO 2 and Y 2 o 3 The molar ratio is 95:5, and the particle diameter is about 2-3 microns), 41 parts by weight of the above-mentioned magnesium aluminum spinel (MgAl 2 o 4 ) powder, 3 parts by weight Al 2 o 3 Powder, 3 parts b...

Embodiment 2

[0037] This embodiment is used to illustrate the preparation of the platinum electrode of the automobile oxygen sensor provided by the present invention

[0038] (1) Take a certain amount of Al(OH) with a particle diameter of about 1 micron 3 The solid powder is poured into an alumina burning boat and pre-fired at 260°C for 48 hours; the obtained powder and MgO powder with a particle diameter of 1 micron are mixed and ball milled at a molar ratio of 1:1 for 10 hours, and then heated at 1300 ℃ roasting for 2 hours; after cooling, magnesium aluminum spinel powder is obtained. The prepared magnesia-aluminum spinel is pulverized, classified and screened to keep the powder of about 1 micron.

[0039] (2) 50 parts by weight of Y-ZrO 2 Micropowder (ZrO 2 and Y 2 o 3 The molar ratio is 97:3, and the particle diameter is about 2-3 microns), 38 parts by weight of the above-mentioned magnesium aluminum spinel (MgAl 2 o 4 ) powder, 2 parts by weight of Al 2 o 3 Powder, 3 parts by...

Embodiment 3

[0042] This embodiment is used to illustrate the preparation of the platinum electrode of the automobile oxygen sensor provided by the present invention

[0043] (1) Take a certain amount of Al(OH) with a particle diameter of about 1 micron 3 The solid powder is poured into an alumina crucible and pre-fired at 280°C for 48 hours; the obtained powder and MgO powder with a particle diameter of about 1 micron are mixed and ball milled at a molar ratio of 1:1 for 10 hours, and then heated at 1360°C Roasting for 2 hours; after cooling, magnesium aluminum spinel powder is obtained. The prepared magnesia-aluminum spinel is pulverized, classified and screened to keep the powder of about 1 micron.

[0044] (2) 55 parts by weight of Y-ZrO 2 Micropowder (ZrO 2 and Y 2 o 3 The molar ratio is 92:8, the particle diameter is about 2-3 microns), 33 parts by weight of MgAl 2 o 4 Powder, 2 parts by weight Al 2 o 3 Powder, 3 parts by weight SiO 2 powder, 1 weight part K 2 CO 3, 3 par...

technical field

[0001] The invention relates to a platinum electrode of an oxygen sensor and a preparation method thereof, more particularly, the invention relates to a platinum electrode of an automobile oxygen sensor and a preparation method thereof. Background technique

[0002] In the three-way control system of the automobile engine, the electronically controlled fuel supply unit, the oxygen sensor, and the three-way catalyst are the cores of the control system. In the modern engine EFI system, the most used oxygen sensor is to detect the theoretical air-fuel ratio oxygen sensor, which mainly keeps the engine working near the theoretical air-fuel ratio, so that the three-way catalyst is in the best working range. The oxygen sensor widely used at present is the concentration type zirconia oxygen sensor, which mainly adopts a tubular structure, and the zirconia tube of the sensitive element can be made by injection molding or cold isostatic pressing.

[0003] In actual u...

Examples

Embodiment 1

[0032] This example is used to illustrate the preparation of the platinum electrode of the automobile oxygen sensor provided by the present invention.

[0033] (1) Take a certain amount of Al(OH) with a particle diameter of about 1 micron 3 The solid powder is poured into an alumina burning boat and pre-fired at 250°C for 72 hours; the obtained powder is mixed with MgO powder with a particle diameter of about 1 micron in a molar ratio of 1:1 and ball milled for 10 hours, and then heated at 1350 ℃ roasting for 3 hours; after cooling, magnesium aluminum spinel powder is obtained. The prepared magnesia-aluminum spinel is pulverized, classified and screened to keep the powder of about 1 micron.

[0034] (2) 45 parts by weight of Y-ZrO 2 Micropowder (ZrO 2 and Y 2 o 3 The molar ratio is 95:5, and the particle diameter is about 2-3 microns), 41 parts by weight of the above-mentioned magnesium aluminum spinel (MgAl 2 o 4 ) powder, 3 parts by weight Al 2 o 3 Powder, 3 parts b...

Embodiment 2

[0037] This embodiment is used to illustrate the preparation of the platinum electrode of the automobile oxygen sensor provided by the present invention

[0038] (1) Take a certain amount of Al(OH) with a particle diameter of about 1 micron 3 The solid powder is poured into an alumina burning boat and pre-fired at 260°C for 48 hours; the obtained powder and MgO powder with a particle diameter of 1 micron are mixed and ball milled at a molar ratio of 1:1 for 10 hours, and then heated at 1300 ℃ roasting for 2 hours; after cooling, magnesium aluminum spinel powder is obtained. The prepared magnesia-aluminum spinel is pulverized, classified and screened to keep the powder of about 1 micron.

[0039] (2) 50 parts by weight of Y-ZrO 2 Micropowder (ZrO 2 and Y 2 o 3 The molar ratio is 97:3, and the particle diameter is about 2-3 microns), 38 parts by weight of the above-mentioned magnesium aluminum spinel (MgAl 2 o 4 ) powder, 2 parts by weight of Al 2 o 3 Powder, 3 parts by...

Embodiment 3

[0042] This embodiment is used to illustrate the preparation of the platinum electrode of the automobile oxygen sensor provided by the present invention

[0043] (1) Take a certain amount of Al(OH) with a particle diameter of about 1 micron 3 The solid powder is poured into an alumina crucible and pre-fired at 280°C for 48 hours; the obtained powder and MgO powder with a particle diameter of about 1 micron are mixed and ball milled at a molar ratio of 1:1 for 10 hours, and then heated at 1360°C Roasting for 2 hours; after cooling, magnesium aluminum spinel powder is obtained. The prepared magnesia-aluminum spinel is pulverized, classified and screened to keep the powder of about 1 micron.

[0044] (2) 55 parts by weight of Y-ZrO 2 Micropowder (ZrO 2 and Y 2 o 3 The molar ratio is 92:8, the particle diameter is about 2-3 microns), 33 parts by weight of MgAl 2 o 4 Powder, 2 parts by weight Al 2 o 3 Powder, 3 parts by weight SiO 2 powder, 1 weight part K 2 CO 3, 3 par...