Pure alpha-phase molybdenum carbide-loaded noble metal catalyst, and preparation method and application thereof

Abstract

The invention discloses a pure alpha-phase molybdenum carbide-loaded noble metal catalyst, and a preparation method thereof. The preparation method comprises the following steps: (1) a noble metal salt solution is mixed with an ammonium paramolybdate water solution, and stirring is carried out; filtering and washing are carried out; and an obtained precipitate is dried, such that a precursor is obtained; (2) the precursor obtained in the step (1) is subjected to a non-equilibrium plasma treatment, such that noble metal-loading molybdenum oxide is obtained; and (3) the noble metal-loading molybdenum oxide obtained in the step (2) is carbonized with a carbon source gas under a temperature of 580-800 DEG C. According to the invention, a traditional roasting process is replaced by the non-equilibrium plasma treatment process. The pure alpha-phase molybdenum carbide-loaded noble metal catalyst can be directly obtained through a one-step carbonization process of the noble metal-loading molybdenum oxide obtained by the treatment process, such that a highly polluting nitridation process is eliminated. The invention also discloses an application of the prepared pure alpha-phase molybdenum carbide-loaded noble metal catalyst in a water gas shift reaction. As a result, the catalyst has excellent water gas shift performance.

Description

technical field [0001] The invention relates to the preparation and application of a molybdenum carbide-supported noble metal catalyst, in particular to a pure α-phase molybdenum carbide-supported noble metal catalyst and its preparation method, as well as its application in water vapor shift reaction. Background technique [0002] The inventor's research group found that in the water vapor shift reaction, pure α-phase molybdenum carbide catalyst (referred to as α-MoC 1-x ) is much more active than pure β-phase molybdenum carbide catalysts (denoted as β-Mo 2 C); pure α-phase gold molybdenum carbide catalyst (recorded as Au / α-MoC 1-x ) has higher catalytic activity than α- and β-phase miscible gold molybdenum carbide catalysts (denoted as Au / MoC x ) catalytic activity, much higher than the pure β-phase gold molybdenum carbide catalyst (recorded as Au / β-Mo 2 C) Catalytic activity. [0003] α-MoC 1-x The synthesis of MoO can only be achieved by a two-step method of nitridi...

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Problems solved by technology

This method has the following disadvantages: ① During the carbonization process, the exchange of lattice nitrogen and carbon atoms of molybdenum nitride needs to be carried out at a relatively high temperature (above 700 ° C), and high temperature will aggravate the polymerization of free carbon on the particle surface and generate carbon deposits. The specific surface area of ​​molybdenum carbide and the exposure of surface catalytic active sites are greatly reduced; ②The operation process is cumbersome and the preparation cycle is long; ③Need to use a strong irritating gas NH 3 , not only corroding equipment but also prone to danger

[0005] So far, the synthesis of pure α-phase molybdenum carbide supported metal catalysts has not been reported by one-step carbonization method (that is, only through carbonization process without first nitriding)

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