合成四氢噻吩非负载Ni-Mo催化剂的制备与表征

采用溶胶-凝胶法制备了非负载Ni-Mo复合氧化物催化剂,采用N2吸附-脱附、X射线衍射(XRD)、红外光谱(FT-IR)、X射线能谱(EDS)和H_2程序升温还原(H_2-TPR)等手段对催化剂进行了表征。在连续流动固定床反应器上,以环丁砜体积分数为10%的乙基苯溶液为原料加氢脱氧合成四氢噻吩为探针反应,考察了不同Mo和Ni的物质的量之比对含硫氧化合物选择性加氢脱氧性能的影响。结果表明:采用溶胶-凝胶法可制备较高比表面积催化剂,活性组分Ni和Mo发生相互作用形成了复合氧化物Ni MoO_4;随着Mo和Ni的物质的量之比的增大,催化剂表面的活性组分Mo的含量先增大后减小,在Mo和Ni的物质的量之比为0.6时,催化剂表面的Mo含量最高,其催化性能较好,该催化剂在230℃,0.3 MPa和液时空速为1 h-1的条件下,环丁砜转化率为91.3%,四氢噻吩选择性为84.1%。

Preparation and Evaluation of Unsupported Ni-Mo Catalysts for Synthesis of Tetrahydrothiophene

Unsupported Ni-Mo composite oxide catalysts were prepared by the sol-gel method, and were characterized using N2 adsorption-desorption, X-ray diffraction(XRD), infrared spectrum(FT-IR), X ray energy spectrum(EDS) and H2 temperature programmed reduction(H2-TPR). In a continuous flow fixed-bed reactor, the effects of Mo/Ni molar ratio and reaction temperature on the hydrodeoxygenation activity were investigated using sulfolane plus ethybenzene solution(emphatically 10% of sulfolane) as a probe compound. The results showed that Ni-Mo composite oxide catalysts prepared by sol-gel method possess higher specific surface area. The composite oxide NiMoO4 was formed by Ni and Mo active components. Mo content on the catalyst surface increased and then decreased with the increase of Mo/Ni ratio.Mo content reached the highest when Mo/Ni ratio was 0.6 at which the catalyst exhibited the highest hydrodeoxygenation activity. Under the conditions of 230℃, 0.3 MPa, liquid hourly space velocity 1 h-1, the conversion of sulfolane and the selectivity of tetrahydrothiophene were 91.3% and 84.1%, respectively.