Ni-Co-P/HAP用于催化水相中香草醛的加氢脱氧反应

Aqueous Phase Hydrodeoxygenation of Vanillin Over Ni-Co-P/HAP Catalyst

采用化学还原法制备了Ni-P、Ni-Co-P非晶态合金催化剂,浸渍法制备了负载型Ni-Co-P/HAP(HAP,羟基磷灰石)非晶态合金催化剂。通过X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、差示扫描量热(DSC)、光学接触角测量等技术对所制备催化剂结构和性能进行了表征。以水相中香草醛的加氢脱氧(HDO)反应为探针,考察了催化剂的催化性能。结果显示,助剂Co的掺入可以有效地增大非晶态合金Ni-Co-P的无序程度,有利于非晶态合金Ni-Co-P的形成,催化剂粒径大小更为均匀,热稳定性得到提高。将非晶态合金Ni-Co-P负载到HAP上,增大了催化剂的比表面积,改善了催化剂的亲水性。在香草醛的加氢脱氧反应中,Ni-Co-P/HAP比Ni-P和Ni-Co-P非晶态合金催化剂表现出更佳的催化活性。当H 2压力2.0 MPa、反应温度150℃、反应时间180 min、催化剂的量0.05 g时,香草醛转化率为100%,2-甲氧基-4-甲基苯酚(MMP)的选择性为92.8%;催化剂循环使用5次后,香草醛转化率仍为100%,MMP的选择性高达84.7%。

Ni-P,Ni-Co-P and supported Ni-Co-P/HAP(HAP,hydroxyapatite)amorphous alloy catalysts were prepared by chemical reduction and impregnation method,and characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM),differential scanning calorimetry(DSC)and optical contact angle measurement.The catalytic performances of these catalysts were evaluated by the aqueous phase hydrodeoxygenation(HDO)of vanillin.Results show that Co additive enhances the extent of long-range disorder effectively and is beneficial to the formation of amorphous alloy Ni-Co-P,while the particle size of the amorphous alloy Ni-Co-P becomes more uniform,improving the thermal stability of the catalyst.Loading amorphous alloy Ni-Co-P on HAP increases the specific surface area and hydrophilicity of the catalyst.In the hydrodeoxygenation of vanillin,Ni-Co-P/HAP exhibits better catalytic activity than Ni-P and Ni-Co-P amorphous alloy catalysts.The conversion of vanillin and the selectivity of 2-methoxy-4-methylphenol(MMP)is 100% and 92.8%,respectively,under the reaction condition of which the pressure of H 2 of 2.0 MPa,the temperature of 150℃,the reaction time of 180 min and the mass of catalyst of 0.05 g.The conversion of vanillin maintains 100% and the selectivity of MMP was 84.7% after the catalyst was recycled for 5 times.