N-doped porous carbon electrocatalyst and process for preparation thereof
The present invention relates to an efficient, non-metal, N-doped porous carbon electrocatalyst for oxygen reduction reaction and a process for the preparation of using g-C 3 N 4 as a nitrogen precursor, metal organic frameworks (MOF) as a carbon template having high specific surface area, large number of active sites and large pore volume.
1. A process for the preparation of an N-doped porous carbon electrocatalysts comprising carbon in the range of 90 to 93% and nitrogen in the range of 7 to 10%:
a. pyrolysing of metal organic frameworks (MOF) to obtain mesoporous carbon (MOFC);
b. mixing and grinding the mesoporous carbon as obtained in step (a) and melamine to get a uniform mixture;
c. dispersing the uniform mixture of step (b) in alcohol in order to get a homogeneous mixture;
d. evaporating solvent by simultaneous heating and stirring the homogeneous mixture as obtained in step (c) till a solid material obtained;
e. heating the solid material as obtained in step (d) in a flow of argon atmosphere to obtain a composite;
f. pyrolysing the composite as obtained in step (e) under argon atmosphere to obtain N-doped porous carbon electrocatalyst;
wherein in step (b) the ratio of the mesoporous carbon and melamine ranges between 1:2 to 1:5.
2. The process as claimed in claim 1 , wherein the MOF is selected from the group consisting of MOF-2, MOF-5.
3. The process as claimed in claim 1 , wherein in step (a) pyrolysis is done at temperature in the range of 900 to 1000° C. at a heating rate of 3 to 5° C./min for period in the range of 2 to 3 h.
4. The process as claimed in claim 1 , wherein in step (c) alcohol is selected from methanol, ethanol, propanol.
5. The process as claimed in claim 1 , wherein in step (c) the dispersion is sonicated for period in the range of 20 to 30 min in a bath type sonicator followed by stirring for period in the range of 6 to 12 h at room temperature in the range of 25 to 30° C.
6. The process as claimed in claim 1 , wherein in step (d) evaporation is performed at temperature in the range of 50 to 60° C.
7. The process as claimed in claim 1 , wherein in step (e) heating is performed at temperature in the range of 300 to 550° C. and flow of argon at a rate of 3 to 5° C./min for period in the range of 2 to 3 h followed by natural cooling to room temperature in the range of 25 to 30° C.
8. The process as claimed in claim 1 , wherein in step (f) pyrolysing at a rate of 3 to 5° C./min for period in the range of 2 to 3 h.
9. The process as claimed in claim 1 , wherein in step (f) heating is carried out at 700-1000° C.