Nitrogen-rich carbon materials with hierarchical porosity were obtained by pyrolyzing melamine-urea-formaldehyde (MUF) resins between 650 and 850 degrees C with a mesoporous silica template, followed by KOH activation under N-2 atmosphere. In the synthesis process, the high nitrogen-containing MUF resins serve not only as carbon precursor but also as nitrogen source, and nitrogen content can be easily controlled by the carbonization temperature. The resulting MUF resins-derived porous carbon(MUFCx) exhibits a high surface area (up to 2563.4 m(2) g(-1)) with nitrogen content varying from 14.25 to 11.68 at.%, respectively. As expected, electrochemical measurements show that the sample carbonized at 750 degrees C exhibits improved capacitance properties, such as an enlarged specific capacity (375 F g(-1) at 0.5 A g(-1)), excellent rate capability (272 F g(-1) at 10 A g(-1)), as well as excellent cycling retention (only 5% loss after 2000 cycles). Furthermore, an as-fabricated MUFC-based symmetric supercapacitor device shows a high energy density of 23.43 W h kg(-1) at a power density of 450 W kg(-1) operated in the voltage range of 0-1.8 V in 1 M Na2SO4 aqueous electrolyte. (C) 2016 Elsevier Ltd. All rights reserved.