Protective internal coatings for porous substrates

A method to form a material having an internally coated porous substrate surface comprising:

• externally contacting a porous substrate containing open pores and channels with a non-colloidal solution, the open pores and channels further comprising interconnected mesopores and macropores, the non-colloidal solution is a phosphorus-containing alumina coating precursor, such that the coating precursor forms a liquid film on interior pore walls of the open pores and channels with one or more film thicknesses between 5 nm to 250 nm thick wherein the coating precursor forms the film on the interior pore walls of the open pores and channels without blocking or filling said open pores or channels of mesopores with greater than 30 nm in average diameter and of all macropores of the interconnected mesopores and macropores;
• and
• drying and curing the phosphorus-containing alumina coating precursor to form a layer of phosphorus-containing alumina onto the interior pore walls of the open pores and channels.