Wu Yiling, Zhou Yikun, Tan Kok Bing, Wang Youting, Xu Kaiji, Zheng Xinyi, Li Kaixuan, Tian Jian, Rao Xiaoping, Zhan Guowu
Academy of Advanced Carbon Conversion Technology, College of Chemical Engineering, Huaqiao University, 668 Jimei Avenue, Xiamen, Fujian 361021, P. R. China.
Fujian Provincial Key Laboratory of Biomass Low-Carbon Conversion, Huaqiao University, 668 Jimei Avenue, Xiamen, Fujian 361021, P. R. China.
ACS Appl Mater Interfaces. 2024 Nov 20;16(46):63455-63469. doi: 10.1021/acsami.4c11403. Epub 2024 Sep 19.
In this study, hierarchically porous ZSM-5 catalysts were fabricated by one-pot assembling ZSM-5 particles onto diverse biomass templates (e.g., rice husk, tea seed husk, tung shell, and coconut shell), wherein the biomass template was transformed into bio-SiO or biochar depending on the calcination conditions. The biotemplated ZSM-5 variants, including ZSM-5(RH), ZSM-5(TSH), ZSM-5(TS), and ZSM-5(CS), exhibited significantly improved deoxygenation performance, achieving ∼100.0% deoxygenation efficiency as compared to the untemplated ZSM-5 catalyst (85.3%). Among them, the ZSM-5(TSH) catalyst exhibited the best performance, accompanied by 100% conversion, 99.6% deoxygenation rate, and 82.3% olefin selectivity. Interestingly, the product distribution over biotemplated ZSM-5 was dominant C-C (selectivity of ∼100% in total olefins), while long-chain olefins (C-C) was the major product (selectivity of 57.3%) over the untemplated ZSM-5. Moreover, molecular dynamics (MD) simulations revealed that biotemplated ZSM-5 exhibited superior diffusion coefficients of stearic acid (reaction substrate) and anthracene (coke precursor) compared to the untemplated ZSM-5, indicating higher self-diffusion rates and consequently superior activity and stability in the catalytic pyrolysis reactions. Furthermore, in situ DRIFTS results showed stearic acid over ZSM-5(TSH) primarily was converted to the CH intermediate mainly via the decarboxylation route, followed by dehydrogenation pyrolysis and C-C breaking reactions into C-C products. Overall, this work developed an effective strategy for manufacturing hierarchically porous zeolite catalysts using biomass-derived bio-SiO or biochar as the platform.
在本研究中，通过将ZSM-5颗粒一锅法组装到不同的生物质模板（如稻壳、茶籽壳、桐壳和椰壳）上制备了具有分级孔结构的ZSM-5催化剂，其中生物质模板根据煅烧条件转化为生物SiO或生物炭。生物模板化的ZSM-5变体，包括ZSM-5(RH)、ZSM-5(TSH)、ZSM-5(TS)和ZSM-5(CS)，表现出显著提高的脱氧性能，与未模板化的ZSM-5催化剂（85.3%）相比，脱氧效率达到~100.0%。其中，ZSM-5(TSH)催化剂表现出最佳性能，转化率为100%，脱氧率为99.6%，烯烃选择性为82.3%。有趣的是，生物模板化ZSM-5上的产物分布以C-C为主（在总烯烃中的选择性约为100%），而未模板化ZSM-5上的主要产物是长链烯烃（C-C）（选择性为57.3%）。此外，分子动力学（MD）模拟表明，与未模板化的ZSM-5相比，生物模板化的ZSM-5对硬脂酸（反应底物）和蒽（焦炭前驱体）表现出更高的扩散系数，表明其自扩散速率更高，因此在催化热解反应中具有更高的活性和稳定性。此外，原位漫反射红外傅里叶变换光谱（DRIFTS）结果表明，ZSM-5(TSH)上的硬脂酸主要通过脱羧途径转化为CH中间体，随后通过脱氢热解和C-C断裂反应生成C-C产物。总体而言，这项工作开发了一种有效的策略，以生物质衍生的生物SiO或生物炭为平台制备具有分级孔结构的沸石催化剂。
