A pre-catalyst composition comprising: a) a silica support comprising silica wherein an amount of silica is in a range of from 70 wt. % to 95 wt. % based upon a total weight of the silica support; b) a chromium-containing compound wherein an amount of chromium is in a range of from 0.1 wt. % to 5 wt. % based upon the amount of silica; c) a titanium-containing compound wherein an amount of titanium is in a range of from 0.01 wt. % to 20 wt. % based upon the amount of silica; d) a carboxylic acid wherein an equivalent molar ratio of titanium-containing compound to carboxylic acid is in a range of from 1:1 to 1:10; and e) a nitrogen-containing compound with a molecular formula containing at least one nitrogen atom wherein an equivalent molar ratio of titanium-containing compound to nitrogen-containing compound is in a range of from 1:0.5 to 1:10 and wherein: the nitrogen-containing compound comprises an alkanolamine, an amide, an amine, an alkylamine, an ammonium hydroxide, an aniline, a hydrazide, a hydroxylamine, an imine, a urea, or a combination thereof; or wherein the nitrogen-containing compound comprises acetamide, acryl amide, allyl amine, ammonia, ammonium hydroxide, butyl amine, tert-butyl amine, N,N'-dibutyl urea, creatine, creatinine, diethanol amine, diethylhydroxy amine, diisopropanol amine, dimethylaminoethanol, dimethyl carbamate, dimethyl formamide, dimethyl glycine, dimethylisopropanol amine, N,N'-dimethyl urea, ethanol amine, ethyl amine, glycol amine, hexyl amine, hydroxyamine, imidazole, isopropanol amine, methacryl amide, methyl amine, N-methyl aniline, N-methyl-2-propanol amine, methyldiethanol amine, methyl formamide, propyl amine, 2-propanol amine, pyrazole, pyrrolidine, pyrrolidinone, succinimide, tetraethylammonium hydroxide, tetramethylammonium hydroxide, triethanol amine, triisopropanol amine, trimethyl amine, urea, 1,8-diazabicyclo[5.4.0]undec-7-ene, or a combination thereof. a) a silica support comprising silica wherein an amount of silica is in a range of from 70 wt. % to 95 wt. % based upon a total weight of the silica support; b) a chromium-containing compound wherein an amount of chromium is in a range of from 0.1 wt. % to 5 wt. % based upon the amount of silica; c) a titanium-containing compound wherein an amount of titanium is in a range of from 0.01 wt. % to 20 wt. % based upon the amount of silica; d) a carboxylic acid wherein an equivalent molar ratio of titanium-containing compound to carboxylic acid is in a range of from 1:1 to 1:10; and e) a nitrogen-containing compound with a molecular formula containing at least one nitrogen atom wherein an equivalent molar ratio of titanium-containing compound to nitrogen-containing compound is in a range of from 1:0.5 to 1:10 and wherein: the nitrogen-containing compound comprises an alkanolamine, an amide, an amine, an alkylamine, an ammonium hydroxide, an aniline, a hydrazide, a hydroxylamine, an imine, a urea, or a combination thereof; or wherein the nitrogen-containing compound comprises acetamide, acryl amide, allyl amine, ammonia, ammonium hydroxide, butyl amine, tert-butyl amine, N,N'-dibutyl urea, creatine, creatinine, diethanol amine, diethylhydroxy amine, diisopropanol amine, dimethylaminoethanol, dimethyl carbamate, dimethyl formamide, dimethyl glycine, dimethylisopropanol amine, N,N'-dimethyl urea, ethanol amine, ethyl amine, glycol amine, hexyl amine, hydroxyamine, imidazole, isopropanol amine, methacryl amide, methyl amine, N-methyl aniline, N-methyl-2-propanol amine, methyldiethanol amine, methyl formamide, propyl amine, 2-propanol amine, pyrazole, pyrrolidine, pyrrolidinone, succinimide, tetraethylammonium hydroxide, tetramethylammonium hydroxide, triethanol amine, triisopropanol amine, trimethyl amine, urea, 1,8-diazabicyclo[5.4.0]undec-7-ene, or a combination thereof.