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用色谱连续技术,在227～321 ℃下研究了甲醇在Ag~0Y,Ag(I)Y 分子筛1的表面反应。 O结果表明,当有氧存在时,在具有LM酸中心的Ag~0Y ,第一个甲醇分子吸附在Ag Ag H——O—CH_3 /O上形成Ag Ag,该吸附态再解离为Ag-OH和Ag—OCH_3;第二个甲醇分子则吸附在 H分子筛的L酸中心上,形成Y…O—CH_3,相互间脱水后生成二甲醚。根据实验结果,还讨论了在氧存在下,甲醇在具有B酸中心的分子筛上生成甲醛的机理。所提出的机理均能满意地解释所得的实验事实。
The surface reactions of methanol on Ag ~ 0Y and Ag (I) Y zeolites 1 were studied at 227 ~ 321 ℃ by using chromatographic continuous technique. O results show that in the presence of oxygen, the first methanol molecule is adsorbed on Ag Ag H-O-CH 3 / O at Ag ~ 0Y with the LM acid center, and the adsorbed state dissociates Is Ag-OH and Ag-OCH 3; the second methanol molecule is adsorbed on the L acid center of H zeolite to form Y ... O-CH 3, dehydrated to form dimethyl ether. Based on the experimental results, the formation mechanism of formaldehyde on molecular sieve with B acid center in the presence of oxygen was also discussed. The proposed mechanism can satisfactorily explain the experimental facts obtained.