CAJ | 학술논문

研究了负载型Pd-杂多酸催化剂对乙烯直接氧化合成醋酸的催化作用，由固定床反应器考评其催化性能，借助XRD对催化剂进行表征。结果表明：以SiO2为载体，经引入助催化剂Te和Cr，当催化剂组成为wPd=0.03、wHSiW=0.60(以载体质量为基准)及Te∶Pd=1∶20、Cr∶Pd=1∶30(原子比)时，催化剂具有较理想的活性与选择性，乙烯的转化率与醋酸的选择性分别达3.5%和84.1%，醋酸单程时空收率157.8g/(L.h)。
연구료부재형Pd-잡다산최화제대을희직접양화합성작산적최화작용，유고정상반응기고평기최화성능，차조XRD대최화제진행표정。결과표명：이SiO2위재체，경인입조최화제Te화Cr，당최화제조성위wPd=0.03、wHSiW=0.60(이재체질량위기준)급Te∶Pd=1∶20、Cr∶Pd=1∶30(원자비)시，최화제구유교이상적활성여선택성，을희적전화솔여작산적선택성분별체3.5%화84.1%，작산단정시공수솔157.8g/(L.h)。
The effect of Pd-HSiW-Cr-Te/SiO2 on direct oxidation of ethylene to acetic acid was researched in a fixed-bed reactor, and the catalyst was investigated by XRD. The results showed that Pd-HSiW-Cr-Te/SiO2 was an ideal catalyst for direct oxidation of C2H4 to acetic acid. Pd and HSiW were the necessary active components and had excellent effect, the suitable contents of them were wPd=0.03 and wHSiW=0.60(both based on carrier weight). In order to improve the catalytic performance of Pd-HSiW/SiO2, a series of promotors were studied. As a consequence, Te and Cr had excellent effect. By adding trace Te and Cr, the by-products CO2 and CH3CHO could be decreased greatly. The suitable contents of Te and Cr were Te∶Pd=1∶20 and Cr∶Pd=1∶30(atom ratio). It was discovered by XRD that on the catalyst there was an active structure between Pd and HSiW, and the form of Te and Cr was in oxidative state: Te2O5 and CrO2. When the reaction conditions were as follows: T=190°C,p=0.80MPa,SV=4 000h-1, and the composition of reaction mixture gas was C2H4∶O2∶N2∶H2O=50∶6∶14∶30(mol ratio). The catalyst had ideal catalytic performance: the conversion of C2H4 and the selectivity of acetic acid could reach 3.5% and 84.1% respectively, and the by-products CO2 and CH3CHO were 12.4% and 1.1%. The once-through space time yield of acetic acid could reach 157.8g/(L.h).