Superficially porous particles and methods for forming superficially porous particles

A plurality of superficially porous particles, each of the plurality of superficially porous particles comprising:

• a solid core;
• and
• a layered porous shell disposed on and radially outward of the solid core;
• wherein:
• the layered porous shell includes a porous inner layer and a plurality of porous outer layers disposed on and radially outward of the porous inner layer, each of the plurality of porous outer lavers being distinct from one another across an interlayer boundary;
• the layered porous shell includes a first inorganic oxide;
• the porous inner layer includes an inner layer thickness of less than 300 nm;
• the plurality of porous outer layers includes a cumulative outer layer thickness ranging from 1 to 100 times the inner layer thickness;
• the layered porous shell constitutes from 10 vol % to 90 vol % of the plurality of superficially porous particles;
• the plurality of porous outer layers includes a predominately radial pore orientation;
• the plurality of porous outer layers includes an outer layer pore structure which is more organized than an inner layer pore structure of the porous inner layer;
• the layered porous shell includes a fibrous shell skeleton having a shell skeleton thickness greater than 1 nm;
• and
• the layered porous shell includes at least one structural or physical characteristic selected from the group consisting of layer thickness, skeleton thickness, pore orientation, pore size distribution, pore size, pore volume, surface area, and density which changes between the porous inner layer and the plurality of porous outer layers.