CAJ | 학술논문

为考察溶胶凝胶法制备的Co-Mo二元硫化物对H_2S气体的电催化活性,通过循环伏安法和Tafel曲线分析对铂载不同Co、Mo掺杂比的电催化剂进行表征.结果表明,不同阳极电催化剂交换电流密度J_0由大到小依次为,铂载n(Co):n(Mo)=2:3、铂载n(Co):n(Mo)=2:1、铂载n(Co):n(Mo)=1:1和铂,即铂载n(Co):n(Mo)=2:3阳极电催化剂具有较好的活性,这与循环伏安曲线测试结果一致.电解质溶液pH值为6～7时,随着温度的升高铂载n(co):n(Mo)=2:3阳极电催化剂活性呈现上升的趋势.优化后的Co、Mo掺杂原子比约为0.66,此类电催化剂在操作温度80℃下,交换电流密度为1.318mA/cm~2,表观活化焙值为616.6 kJ/mol .研究表明,铂载钴钼二元硫化物适合作为低温H_2S燃料电池阳极电催化剂,其中Co、Mo掺杂比对电催化活性影响较大.
위고찰용효응효법제비적Co-Mo이원류화물대H_2S기체적전최화활성,통과순배복안법화Tafel곡선분석대박재불동Co、Mo참잡비적전최화제진행표정.결과표명,불동양겁전최화제교환전류밀도J_0유대도소의차위,박재n(Co):n(Mo)=2:3、박재n(Co):n(Mo)=2:1、박재n(Co):n(Mo)=1:1화박,즉박재n(Co):n(Mo)=2:3양겁전최화제구유교호적활성,저여순배복안곡선측시결과일치.전해질용액pH치위6～7시,수착온도적승고박재n(co):n(Mo)=2:3양겁전최화제활성정현상승적추세.우화후적Co、Mo참잡원자비약위0.66,차류전최화제재조작온도80℃하,교환전류밀도위1.318mA/cm~2,표관활화배치위616.6 kJ/mol .연구표명,박재고목이원류화물괄합작위저온H_2S연료전지양겁전최화제,기중Co、Mo참잡비대전최화활성영향교대.
This article is dedicated to present sol-gel method for preparing precursor powder of Co-Mo binary sulfides as anode catalysts, which can then be vulcanized in H_2S atmosphere. While investigating the electro-catalytic activity of these anode catalysts in different Co-Mo ratios coated on platinum, the cyclic voltammetry (CV) method and Tafel curve method were applied to test the validity of the catalysts. As a corrosive, noxious gaseous pollutant with unpleasant smell, H_2S has been recently utilized as fuel gas fed into anode chamber of fuel cell to recover e|ectric energy. Experimenting with the various anode materials in hoping to obtain those with good electro-catalytic activities, and then comparing the peak current ( I_(peak) )obtained from CV curve, a conclusion have been reached that the experimental results are in qualitative conformity with the descriptive data of the different corresponding anode catalysts, which can be or dered as follows: n (Co) : n (Mo) = 2: 3 coated on platinum > n (Co) : n (Mo) = 2 : 1 coated on platinum > n (Co) : n (Mo) = 1 : 1 coated on platinum > Pt. The above comparison also indicates that anode catalyst, n(Co): n(Mo) = 2:3 coated on platinum can be chosen as the best one for the electro-catalytic activity. Furthermore, the anode catalyst activity tends to become better at higher temperatures, when pH = 6 ～ 7 in the electrolyte solution. On the other hand, the exchange current density (J_0) obtained from Tafel curve confirms the aforementioned facts quantitatively. As a result, the optimized Co-Mo ratio of anode catalysts should be about 0.66. At the operating temperatures for fuel cells, for example, at 80 ℃, the J_0 value of optimized anode catalyst is expected to reach 1.318 mA/cm~2, while apparent activation enthalpy, △_rH~*, can also be as low as 616.6 kJ/mol. This means that lower activation energy is needed when H2S is electrochemically oxidized on the optimized anode catalyst. In addition, CO-Mo binary sulfides can also be used as anode catalysts when H_2S is electrolyzed or electrochemically oxidized, and the optimized Co-Mo ratio can be obtained before coated on the platinum.Further research remains needed to analyze the electron and total conductivity of the anodes as fuel cells.