• 作者： Jehng, Jih-Mirn; Chen, Sung-Ching; Liu, Yu-Chern
• 中文摘要： 由添加CrO/sub 3,/Nb/sub 2/O/sub 5,/WO/sub 3/添加物於被擔持釩氧化物覆載於混合氧化物載體觸媒中之拉曼光譜得知CrO/sub 3/形成一表面CrO/sub 3/層於觸媒表面，而Nb/sub 2/O/sub 5/及WO/sub 3/分別形成Nb/sub 2/O/ sub 5/及WO/sub 3/顆粒於觸媒表面。表面CrO/sub 3/分子與被擔持釩氧化物覆載於混合氧化物載體觸媒之V-O-Sn橋式鍵結之相互作用使得表面釩氧化物在甲醇氧化反應條件下完全還原。由於無V/sup +5/原子狀態於反應過程中導致甲醇氧化反應之活性降低。形成Nb/sub 2/O/sub 5/及WO/sub 3/顆粒於觸媒表面亦降低甲醇氧化反應之活性。添加不同添加物會對觸媒之表面酸性基位有不同之影響，但形成新表面酸性基位對甲醇氧化反應之反應機制並無明顯之變化及影響，通常甲醇氧化反應只需單一氧化/還原基位即可進行反應。由溫控程式還原實驗可知，添加物本身之還原能力對被擔持釩氧化物於此混合氧化物載體觸媒之還原能力有影響作用。
• 英文摘要： In situ Raman studies of the CrO/sub 3/, Nb/sub 2/O/sub 5/, and WO/sub 3/-V/sub 2/O/sub 5//SnO/sub 2//SiO/sub 2/ catalysts have revealed that chromium oxide forms a surface CrO/sub 3/ overlayer and niobium oxide and tungsten oxide form bulk Nb/sub 2/O/sub 5/ and WO/sub 3/ particles, respectively, on the surface. The interaction of the surface CrO/sub 3/ species with the V-O-Sn bridging bond in the V/sub 2/O/sub 5//SiO/sub 2/ catalyst induces the total reduction of the surface vanadium oxide species during methanol oxidation. The absence of V/sup +5/ atom in the catalyst during reaction conditions results in a lower reactivity of the methanol oxidation reaction. The formation of bulk Nb/sub 2/O/sub 5/ and WO/sub 3/ particles on the V/sub 2/O/sub 5//SnO/sub 2//SiO/sub 2/ surface also decrease methanol oxidation reactivity. The formation of new surface acid sites on the promoted-V/sub 2/O/sub 5//SnO/sub 2//SiO/sub 2/ catalysts does not alter the reaction mechanisms toward the acid site's product (CH/sub 3/OCH/sub 3/), and only one site (redox) is needed to perform the methanol oxidation reaction. TPR studies indicate that the reducibility of the surface vanadium oxide species is affected by the reducibility of the secondary metal oxide.
• 中文關鍵字： 釩氧化物; 混合氧化物; 拉曼光譜; 還原性; 表面酸性; 甲醇氧化
• 英文關鍵字： Vanadium Oxide; Mixed Oxide; Raman Spectroscopy; Reducibility; Surface Acidity; Methanol Oxidation