A mixture of triphenylamine (NPh3) and zeolite Y was thermally treated in an autoclave at 423 K, resulting in the inclusion of NPh3 into the supercage of zeolite Y in 2 h, up to 20 wt % (1.5 NPh3 molecules per supercage). The overall phenomena were close to those observed in the inclusion of triphenylphosphine (PPh3) into the supercage of zeolite Y.