Nowadays,hierarchically macro-/meso-/microporous 3D carbon materials have been paid more attention due to their imaginative application potential in specific electrochemistry.Here,we report a dualtemplate strategy usi...Nowadays,hierarchically macro-/meso-/microporous 3D carbon materials have been paid more attention due to their imaginative application potential in specific electrochemistry.Here,we report a dualtemplate strategy using eutectic NaCl/ZnCl2 melt as airtight and swelling agent to obtain 3D mesoporous skeleton structured carbon from renewable lignin.The prepared lignin-derived biocarbon material(LN-3-1)has a high specific surface area(1289 m^2 g^-1),a large pore volume(2.80 cm^3 g^-1),and a well-connected and stable structure.LN-3-1 exhibits extremely high activity and stability in acidic medium for oxygen reduction reaction(ORR),superior to Pt/C catalyst and most non noble-metal catalysts reported in recent literatures.The prepared carbon material was used as a cathode catalyst to assemble a H2-O2 single fuel cell,and its excellent catalytic performance has been confirmed with the maximum power density of 779 mW cm^-2,which is one of the highest power densities among non-metallic catalysts so far.Density functional theory(DFT)calculations indicate that the synergy of chlorine and nitrogen reconciles the intermediate adsorption energies,leading to an appropriate theoretical ORR onset potential.We develop a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in proton-exchange membrane fuel cells.展开更多
Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry.Here,we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using...Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry.Here,we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using bagasse lignin,denoted as lignin-derived carbon(LC).By adjusting the ratio of nitrogen source and annealing temperature,we obtained the ultrathin graphitic lignin carbon(LC-4-1000)with abundant wrinkles with high surface area of 1208 m2g_1 and large pore volume of 1.40 cm3g_1.In alkaline medium,LC-4-1000 has more positive half-wave potential and nearly current density compared to commercial Pt/C for oxygen reduction reaction(ORR).More importantly,LC-4-1000 also exhibits comparable activity and superior stability for ORR in acid medium due to its high graphitic N ratio and a direct four electron pathway for ORR.This study develops a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in fuel cells.展开更多
Nanoshell-containing carbon (NSCC) is one of the Pt-surrogate catalysts for proton exchange membrane fuel cell (PEMFC) invented by us to promote oxygen reduction reaction (ORR), the cathode reaction of the cell. In th...Nanoshell-containing carbon (NSCC) is one of the Pt-surrogate catalysts for proton exchange membrane fuel cell (PEMFC) invented by us to promote oxygen reduction reaction (ORR), the cathode reaction of the cell. In the present study, we selected one of renewable resources, lignin from herbaceous plants as the carbon precursor for NSCC. The lignin was admixed with cobalt phthalocyanine (CoPc), the nanoshell (NS) forming catalyst, and then carbonized at 1000℃. Transmission electron microscopy and X-ray diffraction studies confirmed the formation of NS structure. The ORR activity of the prepared NSCC increased with the amount of CoPc, and the activity of lignin-based NSCC was higher than that of phenol-formaldehyde resin-based NSCC with the same amount of CoPc added. Surface analysis by X-ray photoelectron spectroscopy revealed no metal species on the NSCC but higher N/C ratio for the lignin-based NSCC by two folds. This study shows the possibility of lignin as a precursor of NSCC cathode catalyst for PEMFC.展开更多
基金the financial support from the National Natural Science Foundation of China(No.21373091)the Science and Technology Project of Guangzhou City(No.201704030040).
文摘Nowadays,hierarchically macro-/meso-/microporous 3D carbon materials have been paid more attention due to their imaginative application potential in specific electrochemistry.Here,we report a dualtemplate strategy using eutectic NaCl/ZnCl2 melt as airtight and swelling agent to obtain 3D mesoporous skeleton structured carbon from renewable lignin.The prepared lignin-derived biocarbon material(LN-3-1)has a high specific surface area(1289 m^2 g^-1),a large pore volume(2.80 cm^3 g^-1),and a well-connected and stable structure.LN-3-1 exhibits extremely high activity and stability in acidic medium for oxygen reduction reaction(ORR),superior to Pt/C catalyst and most non noble-metal catalysts reported in recent literatures.The prepared carbon material was used as a cathode catalyst to assemble a H2-O2 single fuel cell,and its excellent catalytic performance has been confirmed with the maximum power density of 779 mW cm^-2,which is one of the highest power densities among non-metallic catalysts so far.Density functional theory(DFT)calculations indicate that the synergy of chlorine and nitrogen reconciles the intermediate adsorption energies,leading to an appropriate theoretical ORR onset potential.We develop a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in proton-exchange membrane fuel cells.
基金financial support from the National Natural Science Foundation of China (Nos. 21476089, 21373091)the Provincial Science and Technology Project of Guangdong (No. 2014A030312007)
文摘Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry.Here,we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using bagasse lignin,denoted as lignin-derived carbon(LC).By adjusting the ratio of nitrogen source and annealing temperature,we obtained the ultrathin graphitic lignin carbon(LC-4-1000)with abundant wrinkles with high surface area of 1208 m2g_1 and large pore volume of 1.40 cm3g_1.In alkaline medium,LC-4-1000 has more positive half-wave potential and nearly current density compared to commercial Pt/C for oxygen reduction reaction(ORR).More importantly,LC-4-1000 also exhibits comparable activity and superior stability for ORR in acid medium due to its high graphitic N ratio and a direct four electron pathway for ORR.This study develops a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in fuel cells.
文摘Nanoshell-containing carbon (NSCC) is one of the Pt-surrogate catalysts for proton exchange membrane fuel cell (PEMFC) invented by us to promote oxygen reduction reaction (ORR), the cathode reaction of the cell. In the present study, we selected one of renewable resources, lignin from herbaceous plants as the carbon precursor for NSCC. The lignin was admixed with cobalt phthalocyanine (CoPc), the nanoshell (NS) forming catalyst, and then carbonized at 1000℃. Transmission electron microscopy and X-ray diffraction studies confirmed the formation of NS structure. The ORR activity of the prepared NSCC increased with the amount of CoPc, and the activity of lignin-based NSCC was higher than that of phenol-formaldehyde resin-based NSCC with the same amount of CoPc added. Surface analysis by X-ray photoelectron spectroscopy revealed no metal species on the NSCC but higher N/C ratio for the lignin-based NSCC by two folds. This study shows the possibility of lignin as a precursor of NSCC cathode catalyst for PEMFC.
