A catalyst complex selected from the group consisting of catalyst complexes I and II, wherein: catalyst complex I corresponds to the formula: M 1 b [M 2 r (X 1) t] c [M 3 (X 2) 6] d • nM 4 x A 1 y • pM 5 w A 2 z • qM 6 g A 3 h wherein: M 1 and M 4 each represent a metal ion independently selected from Zn 2+, Fe 2+, Co +2+, Ni 2+, Mo 4+, Mo 6+, Al +3+, V 4+, V 5+, Sr 2+, W 4+, W 6+, Mn 2+, Sn 2+, Sn 4+, Pb 2+, Cu 2+, La 3+, and Cr 3+; M 2 and M 3 each represent a metal ion independently selected from Fe 3+, Fe 2+, Co 3+, Co 2+, Cr 2+, Cr 3+, Mn 2+, Mn 3+, Ir 3+, Ni 2+, Rh 3+, Ru 2+, V 4+, V 5+, Ni 2+, Pd 2+, and Pt 2+; M 5 represents one or more of gallium, hafnium, manganese, titanium and indium; M 6 represents one or more of aluminum, magnesium, manganese, scandium, molybdenum, cobalt, tungsten, iron, vanadium, tin, titanium, silicon and zinc and is different from M 5; X 1 represents a group other than cyanide that coordinates with the M 2 ion; X 2 represents a group other than cyanide that coordinates with the M 3 ion; A 1 represents a halide, nitrate, sulfate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, perchlorate, isothiocyanate, an alkanesulfonate, an arylenesulfonate, trifluoromethanesulfonate, or a C 1-4 carboxylate; A 2 and A 3 each represents least one alkoxide, aryloxy, carboxylate, acyl, pyrophosphate, phosphate, thiophosphate, amide, oxide, siloxide, hydride, carbamate, halide or hydrocarbon anion; b, c and d are each numbers that reflect an electrostatically neutral complex, provided that b and c each are greater than zero; x and y are integers that balance the charges in the metal salt M 4 x A 1 y; r is an integer from 4 to 6; t is an integer from 0 to 2; n is a number from 0 and 20; p is a number from 0.001 to 10; q is a number from 0.002 to 10; p ÷ q = 0.025 to 1.5; w and z are numbers that balance the charges in the metal salt M 5 w A 2 z, provided that w is from 1 to 4; and g and h are numbers that balance the charges in the metal salt M 6 g A 3 h, provided that w is from 1 to 4; and catalyst complex II is a mixture of a zinc hexacyanocobaltate catalyst, a particulate M 5 metal oxide wherein M 5 is selected from one or more of gallium, hafnium, manganese, titanium or indium and a particulate M 6 metal or semi-metal oxide wherein M 6 is selected from one or more of aluminum, magnesium, manganese, scandium, molybdenum, cobalt, tungsten, iron, vanadium, tin, titanium, silicon and zinc and is different from M 5, wherein the M 5 metal oxide is present in an amount that provides 0.001 to 10 moles of M 5 metal per mole of cobalt provided by the zinc hexacyanocobaltate catalyst and the M 6 metal or semi-metal oxide is present in an amount that provides 0.002 to 10 moles of M 6 metal or semi-metal per mole of cobalt provided by the zinc hexacyanocobaltate catalyst, and the mole ratio of M 5 metal to M 6 metal or semi-metal is 0.025 to 1.5. M 1 and M 4 each represent a metal ion independently selected from Zn 2+, Fe 2+, Co +2+, Ni 2+, Mo 4+, Mo 6+, Al +3+, V 4+, V 5+, Sr 2+, W 4+, W 6+, Mn 2+, Sn 2+, Sn 4+, Pb 2+, Cu 2+, La 3+, and Cr 3+; M 2 and M 3 each represent a metal ion independently selected from Fe 3+, Fe 2+, Co 3+, Co 2+, Cr 2+, Cr 3+, Mn 2+, Mn 3+, Ir 3+, Ni 2+, Rh 3+, Ru 2+, V 4+, V 5+, Ni 2+, Pd 2+, and Pt 2+; M 5 represents one or more of gallium, hafnium, manganese, titanium and indium; M 6 represents one or more of aluminum, magnesium, manganese, scandium, molybdenum, cobalt, tungsten, iron, vanadium, tin, titanium, silicon and zinc and is different from M 5; X 1 represents a group other than cyanide that coordinates with the M 2 ion; X 2 represents a group other than cyanide that coordinates with the M 3 ion; A 1 represents a halide, nitrate, sulfate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, perchlorate, isothiocyanate, an alkanesulfonate, an arylenesulfonate, trifluoromethanesulfonate, or a C 1-4 carboxylate; A 2 and A 3 each represents least one alkoxide, aryloxy, carboxylate, acyl, pyrophosphate, phosphate, thiophosphate, amide, oxide, siloxide, hydride, carbamate, halide or hydrocarbon anion; b, c and d are each numbers that reflect an electrostatically neutral complex, provided that b and c each are greater than zero; x and y are integers that balance the charges in the metal salt M 4 x A 1 y; r is an integer from 4 to 6; t is an integer from 0 to 2; n is a number from 0 and 20; p is a number from 0.001 to 10; q is a number from 0.002 to 10; p ÷ q = 0.025 to 1.5; w and z are numbers that balance the charges in the metal salt M 5 w A 2 z, provided that w is from 1 to 4; and g and h are numbers that balance the charges in the metal salt M 6 g A 3 h, provided that w is from 1 to 4; and catalyst complex II is a mixture of a zinc hexacyanocobaltate catalyst, a particulate M 5 metal oxide wherein M 5 is selected from one or more of gallium, hafnium, manganese, titanium or indium and a particulate M 6 metal or semi-metal oxide wherein M 6 is selected from one or more of aluminum, magnesium, manganese, scandium, molybdenum, cobalt, tungsten, iron, vanadium, tin, titanium, silicon and zinc and is different from M 5, wherein the M 5 metal oxide is present in an amount that provides 0.001 to 10 moles of M 5 metal per mole of cobalt provided by the zinc hexacyanocobaltate catalyst and the M 6 metal or semi-metal oxide is present in an amount that provides 0.002 to 10 moles of M 6 metal or semi-metal per mole of cobalt provided by the zinc hexacyanocobaltate catalyst, and the mole ratio of M 5 metal to M 6 metal or semi-metal is 0.025 to 1.5.