Abstract Metal modification on hierarchical HZSM-5 produced by alkaline desilication was adopted to improve aromatics production from catalytic pyrolysis of cellulose. The influence of alkali concentration in the desilication on catalytic performance of zeolites was first studied. Mild alkaline treatment preserved the micropore structure and acid sites of zeolites when introducing mesopores, while further increase of alkali concentration destroyed the micropores and acidity. The HZSM-5 desilicated by 0.3 M NaOH solution had the best catalytic performance, which increased the aromatics production and BTX selectivity. Then, metal (Fe and Ga) modification on the optimal zeolite was used to further improve the catalytic performance. Fe modification showed negative effect on aromatics production while Ga modification had the positive. Both Fe and Ga modification increased the selectivity of monoaromatics at the expense of polyaromatics. Furthermore, Fe modification mainly enhanced the production of BTX, while Ga modification promoted the formation of both BTX and alkylbenzenes.

中文翻译：

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金属改性多级HZSM-5催化纤维素热解芳烃产量的改进

摘要 采用碱性脱硅法制备多级HZSM-5的金属改性提高纤维素催化热解芳烃产量。首次研究了脱硅过程中碱浓度对沸石催化性能的影响。弱碱处理在引入介孔时保留了沸石的微孔结构和酸位，而进一步增加碱浓度则破坏了微孔和酸度。0.3 M NaOH溶液脱硅的HZSM-5催化性能最好，提高了芳烃产量和BTX选择性。然后，在最佳沸石上使用金属（Fe和Ga）改性以进一步提高催化性能。Fe 改性对芳烃产量有负面影响，而 Ga 改性有积极影响。Fe 和 Ga 改性都以牺牲多芳烃为代价提高了单芳烃的选择性。此外，Fe改性主要提高了BTX的产生，而Ga改性促进了BTX和烷基苯的形成。