Nickel-Catalysed Vapour-Phase Hydrogenation of Furfural, Insights into Reactivity and Deactivation
Nickel-Catalysed Vapour-Phase Hydrogenation of Furfural, Insights into Reactivity and Deactivation
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DOI：
10.1007/s11244-020-01341-9
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发表时间：
2020-07-30
影响因子：
3.6
通讯作者：
Beaumont, Simon K.
中科院分区：
文献类型：
--
作者：
MacIntosh, Kathryn L.;Beaumont, Simon K.
糠醛是一种关键的生物衍生平台分子，其氢化提供了许多重要的化学中间体，这些中间体可以作为来自原油的那些中间体的“直接”替代品或具有所需性质的新型替代品。本文报道了在180 ℃下在标准浸渍镍催化剂上糠醛气相加氢为糠醇的反应，并与亚铬酸铜上的相同反应进行了对比。虽然未改性的镍催化剂对糠醇的选择性如预期的那样比亚铬酸铜低得多，但是镍催化剂在气相中的活性显著更高，并且失活曲线显著相似。在负载型镍催化剂的情况下，基于Ni/SiO（2）上的失活动力学与在较低酸性的Ni/TiO（2）和Ni/CeO 2上观察到的失活动力学的相似性，催化剂载体上的酸性位点对失活的可能贡献被忽略。粉末X射线衍射用于排除烧结作为主要失活途径。使用程序升温氧化观察到催化剂的显著焦化（在16小时内类似于30重量%）。这与焦化催化剂的溶剂萃取分析和红外光谱相结合，指出（反应物或）产物和烃类焦炭的缩聚产物使催化剂失活。这些发现为镍催化剂的靶向改性铺平了道路，以用于这种重要的生物原料到化学品的转化。
Furfural is a key bioderived platform molecule, and its hydrogenation affords access to a number of important chemical intermediates that can act as "drop-in" replacements to those derived from crude oil or novel alternatives with desirable properties. Here, the vapour phase hydrogenation of furfural to furfuryl alcohol at 180 degrees C over standard impregnated nickel catalysts is reported and contrasted with the same reaction over copper chromite. Whilst the selectivity to furfuryl alcohol of the unmodified nickel catalysts is much lower than for copper chromite as expected, the activity of the nickel catalysts in the vapour phase is significantly higher, and the deactivation profile remarkably similar. In the case of the supported nickel catalysts, possible contribution to the deactivation by acidic sites on the catalyst support is discounted based on the similarity of deactivation kinetics on Ni/SiO(2)with those seen for less acidic Ni/TiO(2)and Ni/CeO2. Powder X-ray diffraction is used to exclude sintering as a primary deactivation pathway. Significant coking of the catalyst (similar to 30 wt% over 16 h) is observed using temperature programmed oxidation. This, in combination with the solvent extraction analysis and infrared spectroscopy of the coked catalysts points to deactivation by polymeric condensation products of (reactant or) products and hydrocarbon like coke. These findings pave the way for targeted modification of nickel catalysts to use for this important biofeedstock-to-chemicals transformation.