疏水活性炭负载的镍基加氢催化剂的抗酸性能

摘要

In order to improve activity and acid-resistance of hydrogenationcatalysts, a series of nickel-based catalysts doped with Fe, Mn, Mo and supported by NaBH4-reduced activated carbon (AC-NaBH4) were prepared via an incipient wetness method. They were applied for the hydrogenation of phthalic anhydride, levulinic acid, maleic anhydride, succinic anhydride and trimellitic anhydride. The results show that the Fe doped catalyst containing 5%(wt) Fe and 15%(wt) Ni (5Fe-15Ni/AC-NaBH4) has satisfactory activity and stability, which can be attributed to the hydrophobic surface of AC-NaBH4 that prevents the resulted water from contacting metal surface. This makes the decrease of H+ concentration which eventually reduces Ni corrosion. Furthermore, XRD and TEM analysis prove the formation of Fe-Ni alloy, which is beneficial to the disperse of nickel particles and can effectively inhibit nickel corrosion.%为了解决镍基催化剂在酸性环境下易被酸腐蚀的问题，分别以金属Fe、Mn和Mo作为助剂，以经NaBH 4处理的活性炭作为疏水性载体，采用等体积浸渍法制备了一系列镍基催化剂，并将其应用于苯酐、乙酰丙酸、丁烯二酸酐、丁二酸酐和偏苯三酸酐等酸性介质的加氢反应中，以研究金属助剂和疏水性载体对镍基催化剂抗酸性能和催化性能的影响。结果表明，与Raney Ni相比，Fe和Ni含量分别为5%(wt)和15%(wt)、疏水性活性炭负载的催化剂(5Fe-15Ni/AC-NaBH 4)具有非常突出的催化活性和抗酸稳定性，在酸性反应环境中重复使用多次仍表现了很好的催化性能。这归因于载体的疏水表面能够阻止产生的水与催化剂表面的接触，使金属活性中心氢离子的活度降低，从而减少了金属镍的腐蚀。此外，XRD和TEM表征结果证明催化剂中形成了Fe-Ni合金，这有利于Ni在载体表面的分散，也有效地延缓了催化剂的失活。