During olefin polymerization on supported catalysts, the controlled morphological evolution of the catalyst particle is vital for ensuring optimal product properties and high catalyst activity. We employed non-destructive hard X-ray holotomography to quantitatively assess the 3D morphology of multiple silica-supported hafnocene-based catalyst particles during the early stages of gas-phase ethylene polymerization. Image processing and pore network modeling revealed clear variations in the dimensions and interconnectivity of pristine particles' macropore networks. This, together with apparent differences in the fragmentation behavior of pre-polymerized particles, suggests that the reactivity and morphological evolution of individual particles are largely dictated by their unique support and pore space architectures. By minimizing the structural heterogeneity among pristine catalyst particles, more uniform particle morphologies may be obtained. Significant polymerization activity, observed in the particles' interiors, further implies that appropriate polymerization conditions and catalyst kinetics can guarantee sufficiently high particle accessibilities and thus more homogeneous support fragmentation.

在负载型催化剂上进行烯烃聚合期间，催化剂颗粒的受控形态演变对于确保最佳产品性能和高催化剂活性至关重要。在气相乙烯聚合的早期阶段，我们采用非破坏性硬 X 射线全息术来定量评估多个二氧化硅负载的铪基催化剂颗粒的 3D 形态。图像处理和孔隙网络建模揭示了原始颗粒大孔隙网络的尺寸和互连性的明显变化。这一点，连同预聚合颗粒的碎裂行为的明显差异，表明单个颗粒的反应性和形态演变在很大程度上取决于它们独特的支撑和孔隙空间结构。通过最小化原始催化剂颗粒之间的结构异质性，可以获得更均匀的颗粒形态。在颗粒内部观察到的显着聚合活性进一步意味着适当的聚合条件和催化剂动力学可以保证足够高的颗粒可及性，从而更均匀的载体碎裂。