Method for in-situ synthesis of three-dimensional nanometer palladium catalyst layer through electrode activity biological membrane and application

Abstract

The invention provides a method for in-situ synthesis of a three-dimensional nanometer palladium catalyst layer through an electrode activity biological membrane. At first, a constant-potential culture method is utilized for growing the electrode activity biological membrane on the surface of an anode of an electrolytic tank stably, then the electrode activity biological membrane is soaked into a palladium salt solution, sodium formate is provided to serve as an electron donor, and by controlling the reaction time, the reaction temperature and the divalent palladium concentration, the electrode activity biological membrane three-dimensional nanometer palladium catalyst layer is obtained. The palladium catalyst electrode is applied to organic pollutant electrocatalytic reduction. Catalyst layer metal palladium nanometer particles are spherical, are distributed uniformly, and are mutually connected to form a stable three-dimensional network catalyst layer structure with the electrode activity biological membrane. The prepared catalyst layer can be directly applied to the electrocatalytic reduction reaction of pollutants and has good electrocatalytic reduction activity to nitrobenzene, and the application potential of microorganism nanometer palladium is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of electrochemistry and biological nanomaterials, and specifically relates to a method for synthesizing a three-dimensional nano-palladium catalytic layer in situ with an electrode active biofilm, a palladium catalytic layer prepared according to the method, and a further prepared palladium catalytic layer electrode And the application of palladium catalytic electrode in the electrocatalytic reduction of organic pollutants. Background technique [0002] Due to the scarcity of noble metals and their great application potential in the field of catalysis, the recovery of noble metals and the synthesis of catalysts have attracted widespread attention. The advantages of nanoscale metal particles, such as high specific surface area and high catalytic activity, have made many scholars pay attention to this field. Compared with the traditional chemical preparation process, the method of microbial synthesis of nano ...

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Problems solved by technology

However, in the process of practical application of microbial nano-palladium, at least the following two problems need to be solved: first, how to ensure that microbial nano-palladium is effectively separated from the medium and fixed on the carrier to avoid the loss of microbial nano-palladium, and further Separation and fixation methods will complicate the application process

Although the concept of electrode-immobilized microbial nano-palladium-catalyzed refractory pollutants has great advantages in terms of high-efficiency loading, reduced mass transfer limitations of electron donors, and safety, the "coating method" used in traditional nanomaterial immobilization There are still many problems in the "method": (1) It is difficult for microbial nano-palladium to be evenly distributed on the electrode, which restricts the stable performance of its catalytic effect.

Although the coating method can achieve better results on two-dimensional electrodes with a smaller area, in the actual application process for three-dimensional electrodes with complex surface structures, the coating method is likely to cause dead angles in the distribution and greatly affect the catalytic performance.

(2) The poor conductivity of the microbial cell itself hinders the transfer of electrons between the nano-palladium particles

(3) Microbial nano palladium is easy to lose

The traditional coating method makes the binding force between the bio-palladium and the electrode weak, and it is easy to fall off and fail in the actual application process

Some expensive linking agents, such as perfluoropolystyrene sulfonic acid (Nafion), often need to be added to improve stable adhesion, which not only increases its cost, but also may cause serious consequences such as secondary pollution

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