Preparation Of Metalloid Doped Pd Catalyst And Its Catalytic Application

Formic acid is regarded as the most potential chemical hydrogen storage material because of its high hydrogen content(4.4wt%),non-toxic and easy storage,meanwhile,it can be also used as hydrogen donor for hydrogen transfer reduction of nitroarenes.this paper is devoted to the study of metalloid doped Pd-based catalysts for catalytic hydrogenation of formic acid and the catalytic hydrogen transfer reduction of 4-nitrophenol with formic acid.This paper is composed of two parts:(1)Highly efficient Pd-B-P/C catalyst for decomposition of formic acidThis part has reported a new kind of double doped Pd-based catalyst(Pd-B-P/C),which displayed high activity,selectivity and excellent recycling capacity for decomposition of formic acid.Under optional reaction conditions:303 K,1 mol/L FA and 3 mol/L SF,the turn-over frequency(TOF)of formic acid decomposition over the Pd-B-P/C catalyst reached 798 h-1 in the first 1 hour,which is 3.1 times,2.3 times and 1.6 times than the corresponding values of the counterpart Pd/C catalyst(TOF=261 h-1)?Pd-P/C(TOF=348 h-1)and Pd-B/C(TOF=497 h-1),respectively.GC-9160 gas chromatography was used to detect the gas products and no CO was found,the results showed that the volume fraction of CO in the product was less than 0.01%.This achievement has a great effect on the extensive application of formic acid dehydrogenation in the future.(2)Hydrogen transfer reduction of 4-nitrophenol with formic acid over Pd-B-P/CEnlightened by the mechanism of formic acid decomposition,in this part,we try to use Pd-B-P/C to catalyze the reduction of 4-nitrophenol to 4-aminophenol by using formic acid as hydrogen donor,the results showed that Pd-B-P/C has a good activity in the catalytic hydrogen transfer reduction of 4-nitrophenol with formic acid.Under optional reaction conditions:303 K,0.25 mmol/L 4-NP and 62.5 mmol/L FA,the turn-over frequency(TOF)and conversion rate were 2.45 min-1 and 55.2%in the first 3 minutes,respectively,and the reaction rate constant was 0.3676 min-1,which is superior to the corresponding values of the counterpart Pd/C catalyst(K=0.1847 min-1).The reaction rate constant was further increased to 0.6147 min-1 with addition of sodium formate.Pd-B-P/C also showed good recycle capacity in the reaction,and still showed good catalytic activity after 10 rounds.