Soil samples were taken from depth of 0-12cm in the virgin broad- leaved/Korean pine mixed forest in Changbai Mountain in April, 2000. 20 μL·L-1 and 200 μL·L-1 CH4 and N2O concentration were supplied for a...Soil samples were taken from depth of 0-12cm in the virgin broad- leaved/Korean pine mixed forest in Changbai Mountain in April, 2000. 20 μL·L-1 and 200 μL·L-1 CH4 and N2O concentration were supplied for analysis. Laboratory study on CH4 oxidation and N2O emission in forest soil showed that fresh soil sample could oxidize atmospheric methane and product N2O. Air-dried soil sample could not oxidize atmospheric methane, but could produCt N2O. However, it could oxidize the supplied methane quickly when its concentration was higher than 20 μL·L-1. The oxidation rate of methane was increased with its initial concentration. An addition of water to dry soil caused large pulse of N2O emissions within 2 hours. There were curvilinear correlations between N2O emission and temperature (r2=0.706, p <0.05), and between N2O emission andtwater content (r2=0.2968. p <0.05). These suggested temperature and water content were important factors controlling N2O emission. The correlation between CH4 oxidization and temperature was also found while CH4 was supplied 200 μL·L-1 (r2 =0.3573, p<0.05). Temperature was an important f8Ctor controlling CH4 oxidation. However, when 20 μL·L-1 CH4 was supplied, there was no correlation among CH4 oxidization, N2O emission, temperature and water content.展开更多
The development of novel and effective methods for the activation of methane is fascinating,which offers a promising potential for the sustainable development of chemical industry and the mitigation of greenhouse effe...The development of novel and effective methods for the activation of methane is fascinating,which offers a promising potential for the sustainable development of chemical industry and the mitigation of greenhouse effect.Here we successfully synthesize two-dimensional(2D)Zr/5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin(TCPP)ultrathin nanobelts(UNBs)as a high efficiency catalyst for methane(CH_(4))oxidation to carbon monoxide(CO).The Co-UNBs show well photo-coupled electrocatalytic performances for CH4 activation(CO production rates are 0.171 and 8.416 mmol·g−1·h−1 under dark/visible light,respectively).Density functional theory(DFT)calculations were performed to illustrate the mechanism of photoelectrocatalytic process and the high efficiency oxidation of CH4 to CO.Based on the ultrathin structure and highly efficient catalytic properties,this work provides a prospecting avenue for the design and synthesis of methane oxidation catalyst.展开更多
文摘Soil samples were taken from depth of 0-12cm in the virgin broad- leaved/Korean pine mixed forest in Changbai Mountain in April, 2000. 20 μL·L-1 and 200 μL·L-1 CH4 and N2O concentration were supplied for analysis. Laboratory study on CH4 oxidation and N2O emission in forest soil showed that fresh soil sample could oxidize atmospheric methane and product N2O. Air-dried soil sample could not oxidize atmospheric methane, but could produCt N2O. However, it could oxidize the supplied methane quickly when its concentration was higher than 20 μL·L-1. The oxidation rate of methane was increased with its initial concentration. An addition of water to dry soil caused large pulse of N2O emissions within 2 hours. There were curvilinear correlations between N2O emission and temperature (r2=0.706, p <0.05), and between N2O emission andtwater content (r2=0.2968. p <0.05). These suggested temperature and water content were important factors controlling N2O emission. The correlation between CH4 oxidization and temperature was also found while CH4 was supplied 200 μL·L-1 (r2 =0.3573, p<0.05). Temperature was an important f8Ctor controlling CH4 oxidation. However, when 20 μL·L-1 CH4 was supplied, there was no correlation among CH4 oxidization, N2O emission, temperature and water content.
基金supported by the National Key R&D Program of China(Nos.2017YFA0700101 and 2016YFA0202801)the National Natural Science Foundation of China(Nos.22035004 and 22205061)the XPLORER PRIZE and the China Postdoctoral Science Foundation(No.2019M660608)。
文摘The development of novel and effective methods for the activation of methane is fascinating,which offers a promising potential for the sustainable development of chemical industry and the mitigation of greenhouse effect.Here we successfully synthesize two-dimensional(2D)Zr/5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin(TCPP)ultrathin nanobelts(UNBs)as a high efficiency catalyst for methane(CH_(4))oxidation to carbon monoxide(CO).The Co-UNBs show well photo-coupled electrocatalytic performances for CH4 activation(CO production rates are 0.171 and 8.416 mmol·g−1·h−1 under dark/visible light,respectively).Density functional theory(DFT)calculations were performed to illustrate the mechanism of photoelectrocatalytic process and the high efficiency oxidation of CH4 to CO.Based on the ultrathin structure and highly efficient catalytic properties,this work provides a prospecting avenue for the design and synthesis of methane oxidation catalyst.
