Different electrocatalytic properties of ammonia oxidation catalyst in the organic electrolyte
|School||Nanjing Normal University|
|Course||Physical and chemical|
|Keywords||An electrochemical gas sensor of the current type Ammonia Propylene carbonate Ethylene glycol dimethyl ether Of Pt catalyst Carbon Supported Pt-Ru catalyst Carbon Supported Ir catalyst Carbon Supported Pt-Ir catalysts|
Ammonia has been widely used in industrial production , but ammonia is a toxic gas , even if the concentration of the trace will cause harm to humans . Therefore , monitoring of ammonia in the working and living environment of great significance , so the development of online monitoring ammonia , low cost , high sensitivity and good selectivity amperometric ammonia sensor has a very important significance . In this thesis, a high electro-catalytic performance of the catalyst for ammonia oxidation in organic solvents , development of amperometric ammonia sensor using organic electrolyte assembly and performance testing , the main results obtained are as follows : '1 . Carbon contained Pt (Pt / C) the electrochemical performance of the ammonia oxidation catalyst in propylene carbonate (PC) and ethylene glycol dimethyl ether (DME) in an organic solvent found in the PC and a low viscosity of the DME mixed electrolyte , Pt / C catalyst electrode oxidation of NH3 good electrocatalytic properties , good sensitivity , good selectivity , fast response time , and can withstand high temperatures and low humidity conditions . Two different proportion of carbon contained Pt-Ru (Pt-Ru / C) catalyst in an organic solvent of PC / DME , the electrocatalytic performance of the ammonia oxidation with tetrahydrofuran (THF) complex reduction Preparation of Pt and Ru atom ratio were 1:1,2:1,3:1 and 4:1 , Pt-Ru -containing the total mass percentage of 20% , Pt and Ru alloy formed Pt-Ru / C catalyst. Found in the PC / DME organic solvent , Pt - Ru / C catalyst for the oxidation of NH3 electrocatalytic activity and stability also increases with increasing Ru content . Therefore, when the atomic ratio of Pt and Ru 1:1 Pt-Ru / C catalyst for NH3 oxidation electrocatalytic activity and stability . And CO , NO and NO2 basically NH3 detection without interference , but SO2 and H2S , NH3 detection obvious interference . 3 carbon containing Ir (Ir / C) and the Carbon Supported Pt-Ir (Pt-Ir / C) catalyst for ammonia oxidation electrocatalytic properties found in the PC / DME organic solvent Ir catalyst of higher the NH3 oxidation catalytic activity , but stability is not very good . Electrocatalytic stability of Pt-Ir / C catalyst for ammonia oxidation was significantly better than the Ir / C catalyst .