阅读说明：本技术 一种掺杂型的铯钒碱金属催化剂 (Doped cesium vanadium alkali metal catalyst ) 是由 楼狄明 向倍宏 彭红 万鹏 于 2021-09-22 设计创作，主要内容包括：本发明提供了两种掺杂型的铯钒碱金属催化剂,第一种掺杂型的铯钒碱金属催化剂的促进层碱金属复合物为Cs-(2)SO-(4),还包括活性成分Cs-(2)V-(4)O-(11),基础涂层γ-Al-(2)O-(3),Cs-(2)V-(4)O-(11)的质量分数为18～26wt%,Cs-(2)SO-(4)的质量分数为4～12wt%,γ-Al-(2)O-(3)的质量分数为62～78wt%,将这种催化剂称为7GB2；第二种掺杂型的铯钒碱金属催化剂促进层碱金属复合物为Cs-(2)SO-(4),还包括活性成分CsVO-(3),基础涂层CePO-(4),CsVO-(3)的质量分数为20～28wt%,Cs-(2)SO-(4)的质量分数为6～14wt%,CePO-(4)的质量分数为58～74 wt%,将这种铯钒碱金属催化剂称为8G。本发明通过向铯钒碱金属催化剂中掺杂含Fe/Sb/P/Co/Ge中任意一种杂质,可获得具有较低PM起燃温度的铯钒碱金属催化剂。(The invention provides two doped cesium vanadium alkali metal catalysts, wherein the alkali metal compound of a promoting layer of the first doped cesium vanadium alkali metal catalyst is Cs 2 SO 4 Also comprises an active ingredient Cs 2 V 4 O 11 Base coat of gamma-Al 2 O 3 ，Cs 2 V 4 O 11 Is 18-26 wt%, Cs 2 SO 4 4-12 wt%, gamma-Al 2 O 3 The mass fraction of the catalyst is 62-78 wt%, and the catalyst is named as 7GB 2; the second doped cesium vanadium alkali metal catalyst promoting layer alkali metal compound is Cs 2 SO 4 And also comprises an active ingredient CsVO 3 Basic coating CePO 4 ，CsVO 3 20-28 wt% of Cs 2 SO 4 Mass fraction of6 to 14wt% of CePO 4 The mass fraction of the cesium vanadium alkali metal catalyst is 58-74 wt%, and the cesium vanadium alkali metal catalyst is named as 8G. According to the invention, the cesium vanadium alkali metal catalyst with a lower PM light-off temperature can be obtained by doping any one impurity of Fe/Sb/P/Co/Ge into the cesium vanadium alkali metal catalyst.)

1. A doped cesium-vanadium alkali metal catalyst with a promoting layer containing Cs as alkali metal compound₂SO₄The method is characterized in that: also comprises an active ingredient Cs₂V₄O₁₁Base coat of gamma-Al₂O₃，Cs₂V₄O₁₁Is 18-26 wt%, Cs₂SO₄4-12 wt%, gamma-Al₂O₃The mass fraction of (A) is 62-78 wt%, and the catalyst is named as 7GB 2.

2. In another doped cesium vanadium alkali metal catalyst, the promoting layer alkali metal compound is Cs₂SO₄The method is characterized in that: also comprises an active ingredient CsVO₃Basic coating CePO₄，CsVO₃20-28 wt% of Cs₂SO₄The mass fraction of CePO is 6-14 wt%₄The mass fraction of the cesium vanadium alkali metal catalyst is 58-74 wt%, and the cesium vanadium alkali metal catalyst is named as 8G.

3. A doped cesium vanadium alkali metal catalyst as claimed in claim 1 wherein: also includes an impurity source Fe₂O₃、Sb₂O₅Or NH₄H₂PO₄One of the impurity sources is selected to be mixed with the raw materials according to a certain proportion and then is sintered for 3 hours at a certain temperature, wherein the Fe doped is recorded as 7GB2-1, the Sb doped is 7GB2-2, and the P doped is 7GB 2-3.

4. A doped cesium vanadium alkali metal catalyst as claimed in claim 2 wherein: the solar cell further comprises any one of impurity sources Co and Ge, wherein the Co-doped source is 8G-1, and the Ge-doped source is 8G-2.

Technical Field

The invention relates to the field of catalysts and preparation thereof. In particular to a doped cesium vanadium alkali metal catalyst.

Background

The main components of the particulate matters in the diesel engine exhaust are carbon and organic substances adsorbed on the carbon, the weight is light, the particulate matters can be suspended in the air for a long time, the suspension time is longer as the particle size is smaller, the influence on the environment for a long time is caused, and the particulate matters contain carcinogenic substances, so that the influence on the health of a human body is huge. In 7 months of the year, China will comprehensively implement the national six-emission standard of heavy diesel vehicles, which indicates that the national automobile standard completely enters the national six times, the emission standard is more severe, and the diesel vehicle exhaust aftertreatment technology faces greater challenges and opportunities.

A Diesel Particulate Filter (DPF) in an exhaust gas treatment system is used to trap carbon and other Particulate Matters (PM) in the exhaust gas of a Diesel engine to prevent the PM from being discharged into the atmosphere, and as the PM is deposited in the DPF, an exhaust back pressure is increased, the exhaust gas temperature needs to be periodically increased to burn the PM, and the temperature needs to reach a normal burning temperature of the PM of more than 600 ℃, which is called active regeneration. DPFs are typically coated with a catalyst that catalyzes the combustion of the particulate matter, and this method of burning the particulate matter is known as passive regeneration, as the DPF is capable of catalyzing the combustion of the particulate matter when normal combustion temperatures are not reached. The development of a high performance PM combustion catalyst is key to solving the problem of soot contamination.

Soot combustion catalysts generally include three types of noble metal-based, oxide-based and alkali metal-based, and existing DPF catalysts are basically catalysts containing platinum-based noble metals such as platinum (Pt), palladium (Pd), rhodium (Rh) and the like, and such catalysts have good PM combustion performance and durability. However, platinum group metals are expensive, and in order to reduce the cost of catalysts, researchers in various countries have conducted studies on saving platinum groups and replacing platinum groups in catalysts for purifying automobile exhaust gases. (see non-patent document 1: Yutian politics, et al, "reduction in the amount of platinum group metal used and substitution technology for exhaust gas purification catalyst", automotive technology Vol.63, pp.42-47, 2009)

Patent CN 111804294A relates to a preparation method of a stable potassium-based soot combustion catalyst and an obtained product, and the invention prepares the stable potassium-based soot combustion catalyst (K-HWO) by dipping hexagonal phase tungsten trioxide (HWO) with a pore structure into a potassium (K) salt solution. Compared with a cesium vanadium alkali metal catalyst, the catalyst has poor thermal stability and limited effect of reducing the carbon smoke ignition temperature.

The invention discloses a patent CN 106807385A, which relates to a nest-shaped soot combustion catalyst, wherein the composite oxide type catalyst contains a transition metal element Cu + Ce + Zr, and the soot ignition temperature reduction effect is poor.

JP 3821357B2 reports a metal nitrate molten salt type catalyst supported on a basic carrier, which melts into a liquid phase at a temperature near the reaction temperature with PM, increases the contact area between the catalyst and PM, more effectively burns and removes PM, and catalyzes PM to burn at a lower temperature as the melting point of the molten salt is lower. The molten salt type catalyst is likely to evaporate due to its low melting point, resulting in the catalyst in this patent being less durable than the DPF precious metal catalyst. The molten salt catalyst of the invention of the prior patent CN103501900A provides a molten salt type exhaust gas purifying catalyst with improved durability by using the 1 st complex metal oxide of cesium and vanadium (CsV oxide) and the sulfate containing cesium and an alkaline earth metal as catalyst components, but it has a room for improvement in lowering the PM light-off temperature Tmax, compared with the DPF catalyst to which a platinum group noble metal is added.

Disclosure of Invention

An object of the present invention is to reduce the light-off temperature of PM while ensuring high durability of the catalyst by providing a CDPF catalyst containing no noble metal.

In order to achieve the above object, the present invention provides a first doped cesium vanadium alkali metal catalyst, wherein the promoting layer alkali metal complex is Cs₂SO₄Also comprises an active ingredient Cs₂V₄O₁₁Base coat of gamma-Al₂O₃，Cs₂V₄O₁₁Is 18-26 wt%, Cs₂SO₄4-12 wt%, gamma-Al₂O₃The mass fraction of (A) is 62-78 wt%, and the catalyst is named as 7GB 2.

Further, the method also comprises an impurity source Fe₂O₃、Sb₂O₅Or NH₄H₂PO₄One of the impurity sources is selected to be mixed with the raw materials according to a certain proportion and then is sintered for 3 hours at a certain temperature, wherein the Fe doped is recorded as 7GB2-1, the Sb doped is 7GB2-2, and the P doped is 7GB 2-3.

Providing a second doped cesium vanadium alkali metal catalyst, wherein the promoting layer alkali metal compound is Cs₂SO₄The method is characterized in that: also comprises an active ingredient CsVO₃Basic coating CePO₄，CsVO₃20-28 wt% of Cs₂SO₄The mass fraction of CePO is 6-14 wt%₄The mass fraction of the cesium vanadium alkali metal catalyst is 58-74 wt%, and the cesium vanadium alkali metal catalyst is named as 8G.

Furthermore, the solar cell further comprises any one of impurity sources Co and Ge, wherein the Co-doped source is 8G-1, and the Ge-doped source is 8G-2.

The cesium vanadium alkali metal catalyst with a lower PM light-off temperature can be obtained by doping any impurity of Fe/Sb/P/Co/Ge, wherein Sb-doped 7GB2-2 not only reduces Tmax, but also improves thermal stability, and the improved catalyst is more suitable for serving as a DPF catalyst. By doping Tmax can be reduced by up to 25 ℃ for 7GB2 and 17 ℃ for 8G.

Drawings

Figure 1 is an XRD pattern of the thermal stability of cesium vanadium alkali metal catalyst 7GB 2;

figure 2 XRD pattern of Fe doped 7GB2 for confirmation of peak shift;

fig. 3 XRD pattern of Sb doped 7GB2 for confirmation of peak shift;

FIG. 4 is an XRD plot of the effect of post-firing temperature on 7GB2 doped with Sb;

figure 5 XRD pattern of P doped 7GB2 for confirmation of peak shift;

FIG. 6 is a graph comparing the maximum temperatures of various catalyst examples.

Detailed Description

The technical solution of the present invention is further explained with reference to the drawings and the embodiments.

Adding into 7GB2 raw materialsAn impurity source containing Fe/Sb/P is added, and the manufacturing raw materials of 7GB2 are as follows: cs₂SO₄，VOSO₄TH 100/150; the impurity sources are: fe₂O₃、Sb₂O₅、 NH₄H₂PO₄Selecting one of the impurity sources to mix with the raw materials according to a certain proportion, and then firing the mixture for 3 hours at a certain temperature, wherein the impurity element is M, and the amount ratio of the impurity element to the V element is: 0.5, 1.0, 2.0 and V is element vanadium. Obtaining the cesium vanadium alkali metal catalyst doped with any one of Fe, Sb and P with lower Tmax.

Impurities containing Co and Ge are added into the 8G raw materials to reduce the ignition temperature Tmax of the 8G for catalyzing PM combustion, so that the catalyst has higher catalytic activity. The ratio of the amounts of impurity elements to the amount of V element species is taken as: 0.5, 1.0, 2.0 and V is element vanadium.

Example 1

Preparing raw materials of cesium vanadium alkali metal catalyst 7GB 2: cs₂SO₄，VOSO₄TH100/150, sintered at temperatures of 800 deg.C, 1000 deg.C, 1100 deg.C, respectively, for three hours, to obtain a sintered ceramic body composed of: cs₂SO₄，Cs₂V₄O₁₁，γ-Al₂O₃The catalyst 7GB2 is prepared from the same components, and XRD experiments are carried out on the sintered product, so that the thermal stability of the cesium vanadium alkali metal catalyst 7GB2 is analyzed.

As shown in FIG. 1, the catalyst active substance Cs generated by the 7GB2 catalyst at 800 deg.C₂V₄O₁₁While the XRD pattern of the corresponding product sintered at 1000 ℃ and 1100 ℃ shows a new peak in comparison with the XRD pattern at 800 ℃ at which the active substance Cs is present₂V₄O₁₁Conversion to CsVO₃，γ-Al₂O₃Conversion to alpha-Al₂O₃. 7GB2 at 800 ℃ also has stable catalyst components, and the components of the 7GB2 catalyst at 1000 ℃ and 1100 ℃ are as follows: cs₂V₄O₁₁And Al₂O₃The conversion to other species began and the catalyst was found to be unstable at these two temperatures.

Example 2

The invention is doped with FeIn the case of a cesium vanadium alkali metal catalyst, Fe₂O₃And Cs₂SO₄，VOSO₄Mixing TH100/150 catalyst preparation raw materials, wherein the amount ratio of Fe and V is 2.0, V is vanadium, and sintering the sample at 800 deg.C, 1000 deg.C and 1100 deg.C for 3 hours.

As shown in FIG. 2, the XRD pattern of the sintered product of the catalyst doped with Fe impurity has no peak shift, compared with the XRD pattern of the un-doped sintered product of the catalyst, and the addition of Fe impurity does not affect the generation of the active component of the 7GB2 catalyst.

Example 3

In the embodiment of the cesium vanadium alkali metal catalyst doped with Sb, Sb is added₂O₃And Cs₂SO₄，VOSO₄The TH100/150 catalyst preparation raw materials were mixed, and the samples were sintered at 800 ℃, 1000 ℃ and 1100 ℃ for 3 hours, respectively, with the mass ratio of Sb to V being 2.0.

As shown in fig. 3, when the XRD pattern of the sintered catalyst product doped with Sb impurity is compared with the XRD pattern of the undoped sintered catalyst product, no peak shift occurs, and the addition of Sb impurity does not affect the formation of active component of 7GB2 catalyst.

Sintering at 800 ℃ and 1000 ℃ as shown in FIG. 4, Sb₂O₃With Al₂O₃Reaction to produce AlSbO₄Compared with the 7GB2 catalyst, the thermal stability of the 7GB2-2 catalyst is improved.

Example 4

In the embodiment of the P impurity-doped cesium vanadium alkali metal catalyst, NH is added₄H₂PO₄And Cs₂SO₄，VOSO₄The TH100/150 catalyst preparation raw materials were mixed, and the samples were sintered at 800 ℃ and 1100 ℃ for 3 hours, respectively, with the amount ratio of the P and V materials being 2.0.

As shown in FIG. 5, the XRD pattern of the sintered product of the catalyst doped with P impurity is compared with that of the undoped sintered product of the catalyst, the XRD peak value of the sintered sample at 1100 ℃ is slightly shifted, and the addition of P impurity below 1100 ℃ does not affect the generation of the active component of the 7GB2 catalyst.

Example 5

As shown in fig. 6, after the doping in 7GB2, the generation of active substances is not affected, and the temperature of the soot ignition is reduced by the addition of three impurities, compared with the original 7GB2, the doping is M: tmax of 7GB2-1, 7GB2-2 and 7GB2-3 with V =2.0 is respectively reduced by 16 ℃, 19 ℃ and 25 ℃, and the Tmax is better reduced by the 7GB2-3 doped with Fe.

Example 6

As shown in FIG. 6, the cesium vanadium alkali metal catalyst 8G is doped with Ge impurities, and the active material in the 8G catalyst is CsVO₃After Ge impurity is doped and heat treatment is carried out, the active material of the catalyst becomes CsV_0.95Ge_0.05O₃Or CsV_0.90Ge_0.10O₃. Tmax for 8G is 509 ℃ and CsV_0.95Ge_0.05O₃Tmax of the catalyst used as a catalytically active substance was 495 ℃ and CsV was used_0.90Ge_0.10O₃The Tmax of the catalyst, which is a catalytically active material, was 497 deg.c, and the PM light-off temperature Tmax was significantly decreased after the addition of Co impurities.

Example 7

As shown in FIG. 6, the cesium vanadium alkali metal catalyst 8G was doped with Co impurity, and the active material in the 8G catalyst was CsVO₃After Co impurity is doped and heat treatment is carried out, the catalyst active substance is changed into CsV_0.95Co_0.05O₃(Co₃O₄) Or CsV_0.95Co_0.05O₃(CoSO₄). Tmax for 8G is 509 ℃ and CsV_0.95Co_0.05O₃(Co₃O₄) Tmax of the catalyst used as a catalytically active substance was 500 ℃ and CsV was used_0.95Co_0.05O₃(CoSO₄) The catalyst Tmax, which is a catalytically active material, was 492 c, and the PM light-off temperature Tmax was significantly decreased after the addition of Co impurities.