Preparation method for integral catalyst for selectively oxidizing CO in hydrogen-rich reformed gas

Abstract

The invention discloses a preparation method for an integral catalyst for selectively oxidizing CO in hydrogen-rich reformed gas, and belongs to the field of CO preferential oxidization catalyst preparation. The preparation method for the catalyst comprises the following steps: dissolving salt of Ru and salt of soluble alkali metal or / and alkaline-earth metal in a nitric acid solution, and preheating the mixed solution in a water bath; steeping a dichroite carrier coated with alumina gel in the preheated solution for 5 to 10min, drying the dichroite carrier, preroasting the dichroite carrier at a temperature of between 100 and 160 DEG C for 1 to 3h and then roasting the dichroite carrier at a temperature of between 300 and 1,000 DEG C for 2 to 5h at the atmosphere of inert gases; and reducing the obtained product at a temperature of between 300 and 800 DEG C for 2 to 5h at the atmosphere of H2-inert gas mixture. The method has simple preparation process and low cost; and the obtained catalyst has the characteristics of high activity, high CO selection, low content of noble metal, low ignition temperature, wide temperature range, and capacity of being conveniently applied to a fuel cell system.

Description

technical field [0001] The invention relates to a method for preparing a catalyst for selectively oxidizing CO in hydrogen-rich reformed gas, in particular to a method for preparing a monolithic catalyst for selectively oxidizing CO in hydrogen-rich reformed gas. Background technique [0002] Proton Exchange Membrane Fuel Cell (PEMFC) is a power generation device that directly converts chemical energy into electrical energy by electrochemical reaction. Compared with traditional power generation devices, it has high energy conversion efficiency, no pollution, low noise, adaptability With the advantages of different power requirements, it has broad application prospects as a fixed power supply (such as a power station) and a mobile power supply for electric vehicles, submarines, aerospace, etc. One form of energy. As the fuel of the PEMFC system, hydrogen mainly comes from the reforming reaction of methanol or natural gas, so 2-15% CO will inevitably remain in the hydrogen. ...

AI Technical Summary

Problems solved by technology

[0007] 1. The content of precious metals is too high, causing the cost to rise

[0008]2. Catalyst ignition temperature is too high, catalyst selectivity is low

[0009]3. The active temperature zone is too narrow

[0010]4. Due to the preparation and pretreatment method of the catalyst, the performance of the catalyst is not high

[0011] U.S. Patent US20020147107 invented a catalyst that can be applied to selectively oxidize CO in hydrogen-rich reformed gas. The catalyst is to load Ru on alumina pellets by impregnation method, which can reduce the CO concentration in reformed gas. to less than 50ppm, but the loading of Ru in the catalyst is higher, reaching 0.5-3%

[0012] Chinese patent CN1216796C invented a catalyst that can be applied to selectively oxidize CO in hydrogen-rich reformed gas. The active component of the catalyst is Pt, Ru or The alloy of the two, Pt or Ru is loaded on the support by the method of incipient wetness impregnation, and the obtained reformed gas with reduced CO concentration can be used as fuel for fuel cells, but the loading of noble metals in the catalyst is also high, around 3%

However, the activity of the catalyst is low, and the highest effective working temperature range can only reach 85%, the concentration of CO outlet is too high, and the purified reformed gas still cannot meet the standard as fuel gas for fuel cells

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