Nickel-based materials,including metallic Ni and Ni oxide,have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts,but neither pure Ni nor NiO is ideal for the hydrogen evolution rea...Nickel-based materials,including metallic Ni and Ni oxide,have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts,but neither pure Ni nor NiO is ideal for the hydrogen evolution reaction(HER)and hydrogen oxidation reaction(HOR).In this paper,an oxygen insertion strategy was applied on nickel to regulate its hydrogen electrocatalytic performance,and the oxygen-inserted nickel catalyst was successfully obtained with the assistance of tungsten dioxide support(denoted as O-Ni/WO_(2)).The partial insertion of oxygen in Ni maintains the face-centered cubic arrangement of Ni atoms,simultaneously expanding the lattice and increasing the lattice spacing.Consequently,the adsorption strength of^(*)H and^(*)OH on Ni is optimized,thus resulting in superior electrocatalytic performance of0-Ni/WO_(2)in alkaline HER/HOR.The Tafel slope of O-Ni/WO_(2)@NF for HER is 56 mV dec^(-1),and the kinetic current density of O-Ni/WO_(2)for HOR reaches 4.85 mA cm^(-2),which is ahead of most currently reported catalysts.Our proposed strategy of inserting an appropriate amount of anions into the metal lattice could provide more possibilities for the design of high-performance catalysts.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
Since the two seminal papers were published independently in 2004, high-entropy-alloys(HEAs) have been applied to structural and functional materials due to the enhanced mechanical properties, thermal stability, and e...Since the two seminal papers were published independently in 2004, high-entropy-alloys(HEAs) have been applied to structural and functional materials due to the enhanced mechanical properties, thermal stability, and electrical conductivity. In recent years, HEA nanoparticles(HEA-NPs) were paid much attention to in the field of catalysis for the promoted catalytic activity. Furthermore, the various ratios among the metal components and tunable bulk and surface structures enable HEAs have big room to enhance the catalytic performance. Especially, noble-metal-based HEAs displayed significantly improved performance in electrocatalysis, where the ‘core effects’ were employed to explain the superior catalytic activity. However, it is insufficient to understand the essential mechanism or further guide the design of electrocatalysts. Structure–property relationship should be disclosed for the catalysis on HEA-NPs to accelerate the process of seeking high effective and efficient electrocatalysts. Therefore, we summarized the recent advances of noble-metal-based HEA-NPs applied to electrocatalysis, such as hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, methanol oxidation reaction, ethanol oxidation reaction, formic acid oxidation reaction, hydrogen oxidation reaction, carbon dioxide reduction reaction and nitrogen reduction reaction. For each electrocatalytic reaction, the reaction mechanism and catalyst structure were presented, and then the structure–property relationship was elaborated. The review begins with the development, concept, four ‘core effect’ and synthesis methods of HEAs. Next,the electrocatalytic reactions on noble-metal-based HEA-NPs are summarized and discussed independently. Lastly, the main views and difficulties pertaining to structure–property relationship for HEAs are discussed.展开更多
Phosphorus-doped carbon nanospheres without any metal residues were synthesized and characterized. The results revealed that the doping phosphorus atoms could significantly improve the electrocatalytic activity of gra...Phosphorus-doped carbon nanospheres without any metal residues were synthesized and characterized. The results revealed that the doping phosphorus atoms could significantly improve the electrocatalytic activity of graphitic carbon for the oxygen-reduction reaction （ORR） both in acidic and alkaline media, and the materials exhibited high electrocatalytic activity, long-term stability, and excellent tolerance to crossover effects especially in alkaline media. Quantum mechanics calculations with the density functional theory demonstrated that the changes in charge density and energetic characteristics of frontier orbitals for the P-doped graphene sheet could facilitate the ORR.展开更多
The reduction of CO2 emission is crucial for the mitigation of climate change.A considerable amount of industrial CO2 can be absorbed in the form of carbonates through high-temperature sorption processes.In this regar...The reduction of CO2 emission is crucial for the mitigation of climate change.A considerable amount of industrial CO2 can be absorbed in the form of carbonates through high-temperature sorption processes.In this regard,the efficient conversion of carbonates to value-added products will provide an economically viable method for the sustainable usage of carbon compounds.Herein,we report a promising solution involving the use of a glycerol and ethanol mixture as a hydrogen donor in the dry reforming process with CaCO3 to produce syngas.A series of metal active components,including Ni,Fe,Co,Cu,Pt,Pd,Ru,and Rh,was used to promote this reaction.Ni showed comparable performance with that of Pd,but outperformed Co,Fe,Cu,Rh,Ru,and Pt.Approximately 100%conversion of glycerol and ethanol,~92%selectivity of synthesis gas(H2 and CO),and a H2/CO ratio of^1.2 were achieved over CaCO3 containing10 wt%Ni(10Ni-CaCO3).Meanwhile,the CO2 concentration was less than 5 vol%,indicating that most of the CO2 captured by the carbonate can be transformed into chemicals;however,they cannot simply be emitted.The CO2 released from the decomposition of CaCO3 not only adjusted the ratio of H2 to CO but also eliminated cokes to guarantee the CO2 absorption-conversion cyclic stability in the absence of steam and at high temperatures.展开更多
Hydrogen was produced over noble metal（Ir, Ru, Rh, Pd） catalysts supported on various oxides, including γ-Al2O3, CeO2, ZrO2 and La2O3, via the autothermal reforming reaction of ethanol （ATRE） and oxidative reform...Hydrogen was produced over noble metal（Ir, Ru, Rh, Pd） catalysts supported on various oxides, including γ-Al2O3, CeO2, ZrO2 and La2O3, via the autothermal reforming reaction of ethanol （ATRE） and oxidative reforming reaction of ethanol （OSRE）. The conversion of ethanol and selectivites for hydrogen and byproducts such as methane, ethylene and acetaldehyde were studied. It was found that lanthana alone possessed considerable activity for the ATRE reaction, which could be used as a functional support for ATRE catalysts. It was demonstrated that Ir/La2O3 prevented the formation of methane, and Rh/La2O3 encumbered the production of ethylene and acetaldehyde. ATRE reaction was carried out over La2O3-supported catalysts （Ir/La2O3） with good stability on stream, high conversion, and excellent hydrogen selectivity approaching thermodynamic limit under autothermal condition. Typically, 3.4H2 molecules can be extracted from a pair of ethanol and water molecules over Ir（5wt%）/La2O3. The results presented in this paper indicate that Ir/La2O3 can be used as a promising catalyst for hydrogen production via ATRE reaction from renewable ethanol.展开更多
Environmentally friendly and energy saving treatment of black liquor(BL),a massively produced waste in Kraft papermaking process,still remains a big challenge.Here,by adopting a NieCaOeCa_(12)Al_(14)O_(33) bifunctiona...Environmentally friendly and energy saving treatment of black liquor(BL),a massively produced waste in Kraft papermaking process,still remains a big challenge.Here,by adopting a NieCaOeCa_(12)Al_(14)O_(33) bifunctional catalyst derived from hydrotalcite-like materials,we demonstrate the feasibility of producing high-purity H_(2)(~96%)with 0.9 mol H_(2) mol^(-1) C yield via the sorption enhanced steam reforming(SESR)of BL.The SESRBL performance in terms of H_(2) production maintained stable for 5 cycles,but declined from the 6th cycle.XRD,Raman spectroscopy,elemental analysis and energy dispersive techniques were employed to rationalize the deactivation of the catalyst.It was revealed that gradual sintering and agglomeration of Ni and CaO and associated coking played important roles in catalyst deactivation and performance degradation of SESRBL,while deposition of Na and K from the BL might also be responsible for the declined performance.On the other hand,it was demonstrated that the SESRBL process could effectively reduce the emission of sulfur species by storing it as CaSO_(3).Our results highlight a promising alternative for BL treatment and H_(2) production,thereby being beneficial for pollution control and environment governance in the context of mitigation of climate change.展开更多
基金financially supported by National Natural Science Foundation of China(No.22209049,22075102,22005120)Natural Science Foundation of Guangdong Province(No.2023A1515012804)Fundamental Research Funds for the Central Universities(No.2022ZYGXZR048)。
文摘Nickel-based materials,including metallic Ni and Ni oxide,have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts,but neither pure Ni nor NiO is ideal for the hydrogen evolution reaction(HER)and hydrogen oxidation reaction(HOR).In this paper,an oxygen insertion strategy was applied on nickel to regulate its hydrogen electrocatalytic performance,and the oxygen-inserted nickel catalyst was successfully obtained with the assistance of tungsten dioxide support(denoted as O-Ni/WO_(2)).The partial insertion of oxygen in Ni maintains the face-centered cubic arrangement of Ni atoms,simultaneously expanding the lattice and increasing the lattice spacing.Consequently,the adsorption strength of^(*)H and^(*)OH on Ni is optimized,thus resulting in superior electrocatalytic performance of0-Ni/WO_(2)in alkaline HER/HOR.The Tafel slope of O-Ni/WO_(2)@NF for HER is 56 mV dec^(-1),and the kinetic current density of O-Ni/WO_(2)for HOR reaches 4.85 mA cm^(-2),which is ahead of most currently reported catalysts.Our proposed strategy of inserting an appropriate amount of anions into the metal lattice could provide more possibilities for the design of high-performance catalysts.
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.
基金supported by the National Natural Science Foundation of China (21676100, 22008076)the Guangdong Natural Science Foundation (2017A030312005)。
文摘Since the two seminal papers were published independently in 2004, high-entropy-alloys(HEAs) have been applied to structural and functional materials due to the enhanced mechanical properties, thermal stability, and electrical conductivity. In recent years, HEA nanoparticles(HEA-NPs) were paid much attention to in the field of catalysis for the promoted catalytic activity. Furthermore, the various ratios among the metal components and tunable bulk and surface structures enable HEAs have big room to enhance the catalytic performance. Especially, noble-metal-based HEAs displayed significantly improved performance in electrocatalysis, where the ‘core effects’ were employed to explain the superior catalytic activity. However, it is insufficient to understand the essential mechanism or further guide the design of electrocatalysts. Structure–property relationship should be disclosed for the catalysis on HEA-NPs to accelerate the process of seeking high effective and efficient electrocatalysts. Therefore, we summarized the recent advances of noble-metal-based HEA-NPs applied to electrocatalysis, such as hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, methanol oxidation reaction, ethanol oxidation reaction, formic acid oxidation reaction, hydrogen oxidation reaction, carbon dioxide reduction reaction and nitrogen reduction reaction. For each electrocatalytic reaction, the reaction mechanism and catalyst structure were presented, and then the structure–property relationship was elaborated. The review begins with the development, concept, four ‘core effect’ and synthesis methods of HEAs. Next,the electrocatalytic reactions on noble-metal-based HEA-NPs are summarized and discussed independently. Lastly, the main views and difficulties pertaining to structure–property relationship for HEAs are discussed.
基金supported by the Guangdong Provincial Science and Technology Project of China (2011B010400016)China Postdoctoral Science Foundation (No. 20110490878)
文摘Phosphorus-doped carbon nanospheres without any metal residues were synthesized and characterized. The results revealed that the doping phosphorus atoms could significantly improve the electrocatalytic activity of graphitic carbon for the oxygen-reduction reaction （ORR） both in acidic and alkaline media, and the materials exhibited high electrocatalytic activity, long-term stability, and excellent tolerance to crossover effects especially in alkaline media. Quantum mechanics calculations with the density functional theory demonstrated that the changes in charge density and energetic characteristics of frontier orbitals for the P-doped graphene sheet could facilitate the ORR.
基金supported by the Guangdong Natural Science Foundation(2017A030312005)Science and Technology Program of Guangzhou City(201707010058)。
文摘The reduction of CO2 emission is crucial for the mitigation of climate change.A considerable amount of industrial CO2 can be absorbed in the form of carbonates through high-temperature sorption processes.In this regard,the efficient conversion of carbonates to value-added products will provide an economically viable method for the sustainable usage of carbon compounds.Herein,we report a promising solution involving the use of a glycerol and ethanol mixture as a hydrogen donor in the dry reforming process with CaCO3 to produce syngas.A series of metal active components,including Ni,Fe,Co,Cu,Pt,Pd,Ru,and Rh,was used to promote this reaction.Ni showed comparable performance with that of Pd,but outperformed Co,Fe,Cu,Rh,Ru,and Pt.Approximately 100%conversion of glycerol and ethanol,~92%selectivity of synthesis gas(H2 and CO),and a H2/CO ratio of^1.2 were achieved over CaCO3 containing10 wt%Ni(10Ni-CaCO3).Meanwhile,the CO2 concentration was less than 5 vol%,indicating that most of the CO2 captured by the carbonate can be transformed into chemicals;however,they cannot simply be emitted.The CO2 released from the decomposition of CaCO3 not only adjusted the ratio of H2 to CO but also eliminated cokes to guarantee the CO2 absorption-conversion cyclic stability in the absence of steam and at high temperatures.
基金supported by the National Natural Science Foundation of China (No. 50675070)
文摘Hydrogen was produced over noble metal（Ir, Ru, Rh, Pd） catalysts supported on various oxides, including γ-Al2O3, CeO2, ZrO2 and La2O3, via the autothermal reforming reaction of ethanol （ATRE） and oxidative reforming reaction of ethanol （OSRE）. The conversion of ethanol and selectivites for hydrogen and byproducts such as methane, ethylene and acetaldehyde were studied. It was found that lanthana alone possessed considerable activity for the ATRE reaction, which could be used as a functional support for ATRE catalysts. It was demonstrated that Ir/La2O3 prevented the formation of methane, and Rh/La2O3 encumbered the production of ethylene and acetaldehyde. ATRE reaction was carried out over La2O3-supported catalysts （Ir/La2O3） with good stability on stream, high conversion, and excellent hydrogen selectivity approaching thermodynamic limit under autothermal condition. Typically, 3.4H2 molecules can be extracted from a pair of ethanol and water molecules over Ir（5wt%）/La2O3. The results presented in this paper indicate that Ir/La2O3 can be used as a promising catalyst for hydrogen production via ATRE reaction from renewable ethanol.
基金This work was supported by the Guangdong Natural Science Foundation(2017A030312005)Science and Technology Program of Guangzhou City(201707010058).
文摘Environmentally friendly and energy saving treatment of black liquor(BL),a massively produced waste in Kraft papermaking process,still remains a big challenge.Here,by adopting a NieCaOeCa_(12)Al_(14)O_(33) bifunctional catalyst derived from hydrotalcite-like materials,we demonstrate the feasibility of producing high-purity H_(2)(~96%)with 0.9 mol H_(2) mol^(-1) C yield via the sorption enhanced steam reforming(SESR)of BL.The SESRBL performance in terms of H_(2) production maintained stable for 5 cycles,but declined from the 6th cycle.XRD,Raman spectroscopy,elemental analysis and energy dispersive techniques were employed to rationalize the deactivation of the catalyst.It was revealed that gradual sintering and agglomeration of Ni and CaO and associated coking played important roles in catalyst deactivation and performance degradation of SESRBL,while deposition of Na and K from the BL might also be responsible for the declined performance.On the other hand,it was demonstrated that the SESRBL process could effectively reduce the emission of sulfur species by storing it as CaSO_(3).Our results highlight a promising alternative for BL treatment and H_(2) production,thereby being beneficial for pollution control and environment governance in the context of mitigation of climate change.
