Nanoimaging of pellistors on extended length scale with multi-probe ptychographic tomography

Pellistors have been used commercially for decades. They consist of a miniature Pt coil encased in a porous catalytic bead of Rh-doped ceramic (ca. 800 µm diameter). Since the target gases must diffuse and combust at active Rh sites inside the pores of the ceramic bead, the internal pore structure of the pellistor is integrally linked to sensor performance. Its 3D structure is not adequately studied. For this study, sub-100 nm resolution with a field of view (FOV) over hundred microns is required. So far this is unfeasible. We will make it feasible with the very recently developed technique multi-beam ptychographic tomography and achieve the required resolution over large FOV (≥ 100 μm) to investigate the pore structure of the intact Rh/Al2O3 pellistor at 21 keV.