The hydroisomerization of long-chain -alkanes proves to be an effective approach for the production of renewable second-generation biodiesel, and the development of bifunctional catalysts with synergistic effect between metal and acidic sites was the key to increase the yield of ‐alkanes. Herein, novel hierarchical SAPO-31 nanoparticles (S31-H) were synthesized with varied amounts of the growth inhibitor 1-octyl-3-methylimidazolium chloride ionic liquid (OMIMCl IL) in a one-stage crystallization, and a proposed formation process was discussed. The 0.1Pd/S31-H bifunctional catalysts were prepared by loading only 0.1 wt% Pd based on the S31-H by wetness impregnation method and their catalytic performances were evaluated for the hydroisomerization of -hexadecane. The catalytic performance of 0.1Pd/S31-H based on the S31-H synthesized by adding an appropriate amount of OMIMCl ILs was significantly improved, which can be attributed to the enhanced diffusion originating from its smaller crystal size, higher Pd dispersion, and larger C/C value, which was beneficial for achieving synergistic catalysis. The ‐hexadecane yield of 77.8% and proportion of multi-branched isomers of 51.5%, and catalytic stability within 100 h time on stream was obtained over the 0.1Pd/S31-H at -hexadecane conversion of 89.3%. These catalysts have application potential for the production of second-generation clean biodiesel with excellent low temperature fluidity.

中文翻译：

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扩散和金属-酸协同作用对 Pd/多级结构 SAPO-31 纳米颗粒正十六烷加氢异构化催化行为的影响

长链烷烃加氢异构化被证明是生产可再生第二代生物柴油的有效途径，而开发具有金属和酸性位点协同作用的双功能催化剂是提高烷烃收率的关键。在此，采用不同量的生长抑制剂氯化物 1-辛基-3-甲基咪唑离子液体 (OMIMCl IL) 在一步结晶中合成了新型分级 SAPO-31 纳米粒子 (S31-H)，并讨论了提出的形成过程。采用湿法浸渍法在S31-H的基础上仅负载0.1 wt%的Pd制备了0.1Pd/S31-H双功能催化剂，并评价了其对正十六烷加氢异构化的催化性能。在添加适量OMIMCl ILs合成的S31-H的基础上，0.1Pd/S31-H的催化性能显着提高，这归因于其更小的晶体尺寸、更高的Pd分散度和更大的扩散能力。 C/C值，有利于实现协同催化。 0.1Pd/S31-H的十六烷转化率为89.3%，十六烷收率为77.8%，多支链异构体比例为51.5%，投产100小时内催化稳定性良好。这些催化剂在生产具有优异低温流动性的第二代清洁生物柴油方面具有应用潜力。