双蛋壳Ru纳米颗粒催化L-赖氨酸高效脱羧合成戊二胺

Efficient decarboxylation of L-lysine to cadaverine over Ru nano particle encapsulated in two egg-shell

戊二胺是生物基尼龙56的核心单体,以廉价且产能过剩的L-赖氨酸为原料,通过一步多相催化脱羧合成戊二胺,实现绿色高值化利用。L-赖氨酸脱羧需在强酸体系下进行,提高Ru基催化剂稳定性是共性科学难题之一。采用原位水热合成方法,设计制备双蛋壳包裹的钌催化剂,首先利用FAU孔道实现Ru纳米颗粒的高分散,其次在外层原位生长硅壳silicate-1(S-1),提高催化剂在酸体系下的稳定性。表征结果显示,双蛋壳包裹的Ru/FAU@S-1催化剂外层硅元素明显富集。在戊二胺合成反应中,Ru/FAU@S-1催化活性很高,L-赖氨酸转化率高达81.5%,戊二胺选择性65.8%,循环使用5次后催化效果无明显下降,催化剂稳定性得到显著改善。

Cadaverine is a prime important monomer for development of bio-based nylon 56.The synthesis of cadaverine from low-cost and overcapacity L-lysine is a green and high-value pathway.Efficient and stable catalyst is the key to the chemo-catalytic heterogeneous process for cadaverine.In this work,high dispersion of Ru nanoparticles encapsulated in FAU was synthesized for high catalytic activity.Then,Ru/FAU@S-1 with a shell of the silicalite-1 was synthesized by in situ hydrothermal method to improve stability of catalyst in decarboxylation of L-lysine to cadaverine.In addition,the Ru/FAU encapsulated in all silicon shell had moderate acidity,which was beneficial for the decarboxylation of L-lysine to cadaverine.Finally,the conversion of L-lysine reached 81.5%,and the selectivity of cadaverine reached 65.8%.And,after 5 cycles,there was no significant decrease in catalytic performance of Ru/FAU@S-1.The stability of the catalyst was significantly improved.