Maseko Paula, Cele Mduduzi N, Mdleleni Masikana M
Department of Chemistry, North-West University, Mahikeng, South Africa.
South African Institute for Advanced Materials Chemistry, University of Western Cape, Cape Town, South Africa.
Front Chem. 2025 Feb 25;13:1562436. doi: 10.3389/fchem.2025.1562436. eCollection 2025.
The conversion of carbon dioxide (CO), a major greenhouse gas, into light olefins is crucial for mitigating environmental impacts and utilizing non-petroleum-based feedstocks. Thermo-catalytic CO transformation into valuable chemicals offers a promising solution to this challenge. This study investigates the effect of potassium (K) and manganese (Mn) promoters on CO conversion and CH selectivity over CoFe-ZSM-5 zeolites. Structural characterization via FTIR, pyridine-FTIR, and PXRD confirmed the successful incorporation of K and Mn into CoFe-ZSM-5 at 80°C without significant structural changes to the zeolite framework. BET analysis revealed that metal incorporation did not substantially alter the surface area, while SEM and TEM analyses confirmed the preservation of ZSM-5 spherical morphology. Fixed-bed reactor experiments conducted at 350°C and 20 bar demonstrated that K and Mn synergistically enhanced CO conversion efficiency and selectivity toward CH. The K-Mn/4Fe4Co-ZSM-5 catalyst (modified with 4% Co and 4% Fe) exhibited the highest performance, achieving 97% olefin selectivity. Furthermore, Mn and K promoters reduce the CO selectivity on the Co-Fe-ZSM-5 catalyst. These findings underscore the critical role of K and Mn in facilitating efficient CO activation and directing the reaction pathway toward valuable olefin products.
将主要温室气体二氧化碳（CO）转化为轻质烯烃对于减轻环境影响和利用非石油基原料至关重要。热催化将CO转化为有价值的化学品为应对这一挑战提供了一个有前景的解决方案。本研究考察了钾（K）和锰（Mn）助剂对CoFe-ZSM-5沸石上CO转化和CH选择性的影响。通过傅里叶变换红外光谱（FTIR）、吡啶-傅里叶变换红外光谱（pyridine-FTIR）和粉末X射线衍射（PXRD）进行的结构表征证实，在80°C下K和Mn成功掺入CoFe-ZSM-5中，且沸石骨架没有明显的结构变化。比表面积分析（BET）表明，金属掺入并没有显著改变表面积，而扫描电子显微镜（SEM）和透射电子显微镜（TEM）分析证实了ZSM-5球形形态得以保留。在350°C和20巴下进行的固定床反应器实验表明，K和Mn协同提高了CO转化效率和对CH的选择性。K-Mn/4Fe4Co-ZSM-5催化剂（用4%的Co和4%的Fe改性）表现出最高的性能，烯烃选择性达到97%。此外，Mn和K助剂降低了Co-Fe-ZSM-5催化剂上的CO选择性。这些发现强调了K和Mn在促进CO有效活化以及将反应路径导向有价值的烯烃产物方面的关键作用。
