The invention discloses a pyridinedicarboxylic acid coordinated catalyst, a composite catalyst, a preparation method and application. The general formula of the catalyst is # imgabs0 # B; the catalyst is
calcium ions,
sodium ions,
magnesium ions,
lithium ions,
potassium ions,
ammonium ions, octadecyl dimethyl benzyl
ammonium ions, octadecyl trimethyl
ammonium ions, dodecyl dimethyl benzyl ammonium ions, dodecyl trimethyl ammonium ions, octyl tributyl
phosphonium ions, tetrabutyl
phosphonium ions, hexyl tributyl
phosphonium ions and tributyl ethyl phosphonium ions; the
ionic liquid is a tetrabutyl phosphonium
ion, a tributyl hexyl phosphonium
ion, a tetramethyl ammonium
ion, a
tetraethylammonium ion, a tetrabutyl ammonium ion, a benzyl trimethyl ammonium ion, a benzyl
triphenyl phosphonium ion or a benzyl triethylammonium ion; m is Cr, Mo, V, W, Cu, Fe, Co, Ni or Zr; r is a C1-C10
alkyl group; x is an integer between 1 and 20; and y is an integer between 1 and 40, so that the p-nitrotoluene oxidation reaction selectivity and the p-nitrotoluene conversion rate can be improved.