Method of preparing catalyst containing platinum dispersed on graphene quantum dot containing carrier for direct alcohol fuel cell and catalyst obtained by this method

A catalyst based on Pt dispersed on carrier containing graphen quantum dots (Pt/GQDs), obtained by a method including the following steps:

• step 1:
• prepare a carrier containing graphene quantum dots:
• let the carbon fiber which was ground to powder (carbon fiber powder) react with a mixture of HNO3 70% and H2SO4 98%, with a mass ratio of carbon fiber powder to a volume of HNO3 70% and H2SO4 98% in the range 1:20:30 to 1:60:90, under transducer ultrasound reaction, with a capacity of 750 W and then proceed to a reflux reaction, allow the mixture to cool down to room temperature, neutralize the mixture to pH=7 with NaOH solution in cold ice, then handle neutralizing solution in either preferred of two ways:
• a.1. add the neutralizing mixture to the dialysis membrane 1000 Da, conduct dialysis with deionized water to obtain a liquid containing graphene quantum dots (GQDs) in the dialysis membrane to use as a carrier or
• a.2. crystalize salts present in the neutralizing mixture, filter to remove crystallized crystals from the filtrate to obtain a filtrate containing a mixture of graphene oxide and graphene quantum dot (GO-GQDs) to use as a carrier;
• step 2:
• prepare catalyst based on Pt dispersed on graphene quantum dots:
• add the solution containing the Pt precursor to the liquid obtained in step 1 (a.1) or to the filtrate obtained in step 1 (a.2) then carry out the ultrasonic reaction, after that proceed with Pt ion reduction with NaBH4 0.15 M solution at the temperature ranging from about 25° C. to 80° C., next recover and purify solid products by centrifugation and washing by centrifugation several times with demineralized water, dry in vacuum to obtain the catalyst based on Pt dispersed on graphene quantum dots and catalyst based on Pt dispersed on carrier containing mixture of graphene oxide and graphene quantum dots, respectively, to use as anode catalyst for DAFC;
• and,
• wherein the Pt content in the catalyst ranging from about 1% to 20% by weight.

A catalyst based on Pt dispersed on carrier containing a mixture of graphene oxide and graphene quantum dots graphene (Pt/rGO-GQDs), obtained by a method including the following steps:

• step 1:
• prepare a carrier containing graphene quantum dots:
• let the carbon fiber which was ground to powder (carbon fiber powder) react with a mixture of HNO3 70% and H2SO4 98%, with a mass ratio of carbon fiber powder to a volume of HNO3 70% and H2SO4 98% in the range 1:20:30 to 1:60:90, under transducer ultrasound reaction, with a capacity of 750 W and then proceed to a reflux reaction, allow the mixture to cool down to room temperature, neutralize the mixture to pH=7 with NaOH solution in cold ice, then handle neutralizing solution in either preferred of two ways:
• a.1. add the neutralizing mixture to the dialysis membrane 1000 Da, conduct dialysis with deionized water to obtain a liquid containing graphene quantum dots (GQDs) in the dialysis membrane to use as a carrier or
• a.2. crystalize salts present in the neutralizing mixture, filter to remove crystallized crystals from the filtrate to obtain a filtrate containing a mixture of graphene oxide and graphene quantum dot (GO-GQDs) to use as a carrier;
• step 2:
• prepare catalyst based on Pt dispersed on graphene quantum dots:
• add the solution containing the Pt precursor to the liquid obtained in step 1 (a.1) or to the filtrate obtained in step 1 (a.2) then carry out the ultrasonic reaction, after that proceed with Pt ion reduction with NaBH4 0.15 M solution at the temperature ranging from about 25° C. to 80° C., next recover and purify solid products by centrifugation and washing by centrifugation several times with demineralized water, dry in vacuum to obtain the catalyst based on Pt dispersed on graphene quantum dots and catalyst based on Pt dispersed on carrier containing mixture of graphene oxide and graphene quantum dots, respectively, to use as anode catalyst for DAFC;
• and,
• wherein the Pt content in the catalyst ranging from about 1% to 20% by weight.