Method for fabricating exhaust gas decontamination reactor

Abstract

A method for fabricating an exhaust gas decontamination reactor, which is an exhaust gas decontamination pipe or a exhaust gas decontamination honeycombed structure, comprises steps: respectively coating a cathode layer and an anode layer on an outer wall surface and an inner wall surface of a pipe; and forming an enclosed reducing environment inside an internal channel of the pipe. The method for fabricating an exhaust gas decontamination honeycombed structure comprises steps: respectively coating cathode layers and anode layers on first inner wall surfaces of first passages and second inner wall surfaces of second passages; and forming enclosed reducing environments inside the second passages. Then, the cathode layers function as reaction sites to decontaminate exhaust gas. The present invention needn't arrange a reducing-gas system in the reactor and thus can decrease the volume and fabrication cost thereof.

What is claimed is: 
     
         1 . A method for fabricating an exhaust gas decontamination pipe, comprising steps:
 providing a pipe made of a solid-state oxide and including an internal channel, an inner wall surface surrounding the internal channel, and an outer wall surface far away from the inner wall surface;   coating a green cathode layer, which contains a cathode material, on the outer wall surface, and undertaking a first sintering process to convert the green cathode layer into a cathode layer on the outer wall surface;   coating a green anode layer, which contains an anode material, on the inner wall surface, and undertaking a second sintering process to convert the green anode layer into an anode layer on the inner wall surface; and   forming a reducing environment for the internal channel, and sealing the pipe to enclose the reducing environment and obtain an exhaust gas decontamination pipe, wherein a surface of the cathode layer functions as a reaction site for decontaminating an exhaust gas.   
     
     
         2 . The method for fabricating an exhaust gas decontamination pipe according to  claim 1 , wherein forming the reducing environment comprises steps:
 filling a reducing agent into the internal channel; and   sealing the pipe via sealing elements to enclose the reducing agent inside the internal channel to form the reducing environment.   
     
     
         3 . The method for fabricating an exhaust gas decontamination pipe according to  claim 2 , wherein the reducing agent is selected form a group consisting of solid-state reducing materials, liquid reducing materials, and gaseous reducing materials. 
     
     
         4 . The method for fabricating an exhaust gas decontamination pipe according to  claim 1 , wherein forming the reducing environment comprises steps:
 forming a air pressure lower than 1 atm inside the internal channel; and   sealing the pipe via sealing elements to form the reducing environment inside the internal channel.   
     
     
         5 . The method for fabricating an exhaust gas decontamination pipe according to  claim 1 , wherein the solid-state oxide is selected from a group consisting of fluoride metal oxides, perovskite metal oxides, and combinations thereof. 
     
     
         6 . The method for fabricating an exhaust gas decontamination pipe according to  claim 1 , wherein the cathode material is selected from a group consisting of perovskite metal oxides, fluorite metal oxides, metal-containing perovskite metal oxides, metal-containing fluorite metal oxides, and combinations thereof. 
     
     
         7 . The method for fabricating an exhaust gas decontamination pipe according to  claim 1 , wherein the anode material is selected from a group consisting of fluorite metal oxides, perovskite metal oxides, metal-containing fluorite metal oxides, metal-containing perovskite metal oxides, cermets containing metals and fluorite metal oxides, and combinations thereof. 
     
     
         8 . A method for fabricating an exhaust gas decontamination honeycombed structure, comprising steps:
 providing a honeycombed structure made of a solid-state oxide and including a plurality of tubes and a plurality of separation walls between the tubes;   defining in the tubes a plurality of first passages allowing a exhaust gas to pass and a plurality of unsealed second passages, wherein the second passages surround the first passages;   coating a green cathode layer containing a cathode material on a first inner wall surface of each first passage, and undertaking a first sintering process to convert the green cathode layer into a cathode layer on the first inner wall surface;   coating a green anode layer containing an anode material on a second inner wall surface of each second passage, and undertaking a second sintering process to convert the green anode layer into an anode layer on the second inner wall surface; and   forming reducing environments for the second passages and sealing the second passages to enclose the reducing environments to obtain an exhaust gas decontamination honeycombed structure, wherein surfaces of the cathode layers facing the first passages function as reaction sites to decontaminate the exhaust gas.   
     
     
         9 . The method for fabricating an exhaust gas decontamination honeycombed structure according to  claim 8 , wherein forming the reducing environment comprises steps:
 filling a reducing agent into each second passage; and   sealing the second passage via sealing elements and enclose the reducing agent inside the second passage to form the reducing environments.   
     
     
         10 . The method for fabricating an exhaust gas decontamination honeycombed structure according to  claim 9 , wherein the reducing agent is selected form a group consisting of solid-state reducing materials, liquid reducing materials, and gaseous reducing materials. 
     
     
         11 . The method for fabricating an exhaust gas decontamination honeycombed structure according to  claim 8 , wherein forming the reducing environment comprises steps:
 forming a air pressure lower than 1 atm inside each second passage; and   sealing the second passage via sealing elements to form the reducing environments inside the second passage.   
     
     
         12 . The method for fabricating an exhaust gas decontamination honeycombed structure according to  claim 8 , wherein the solid-state oxide is selected from a group consisting of fluoride metal oxides, perovskite metal oxides, and combinations thereof. 
     
     
         13 . The method for fabricating an exhaust gas decontamination honeycombed structure according to  claim 8 , wherein the cathode material is selected from a group consisting of perovskite metal oxides, fluorite metal oxides, metal-containing perovskite metal oxides, metal-containing fluorite metal oxides, and combinations thereof. 
     
     
         14 . The method for fabricating an exhaust gas decontamination honeycombed structure according to  claim 8 , wherein the anode material is selected from a group consisting of fluorite metal oxides, perovskite metal oxides, metal-containing fluorite metal oxides, metal-containing perovskite metal oxides, cermets containing metals and fluorite metal oxides, and combinations thereof.