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The rational design of the microporous layer (MPL) is very important for the water management of proton exchange membrane fuel cells (PEMFC). The uncertainty of pore structure distribution of MPL originated from the random stacking of particles. To facilitate the water transfer at high current density, it is necessary to improve the capillary force of the gas diffusion layer (GDL). The hierarchical porous structure MPL was designed by coating carbon nanotubes (CNTs) with different length-diameter ratios. In the process of constructing the network structure of CNTs, the polyvinylidene fluoride (PVDF)/N-methylpyrrolidone binder/solvent system alleviates the structural and performance defects caused by the agglomeration via an integrated method of dispersion and binding. The optimal current density of PEMFC at 0.2 V can reach 1913.8 mA/cm2 under the optimal MPL structure. The peak power density of GDL-G PVDF prepared with PVDF is 831.8 W/cm2 which is 8.85% and 15.74% higher than that of GDL-1 PVDF and GDL-2 PVDF with single pore structure, respectively. The lowest mass transfer resistance of GDL-G PVDF is 23.71 mΩ, indicating that it can discharge excess water at the catalyst layer/MPL interface to avoid flooding. This design provided a novel strategy for the stable operation of PEMFC at high current density. [Display omitted] • Two types of carbon nanotubes were used to construct MPL with hierarchical network structure. • Enhanced performance of PEMFC was achieved through enhancing capillary pressure. • The optimized properties of MPL ensure ultra-low mass transport resistance. • The MPLs with PVDF/NMP binder/solvent system facilitate the water and gas transport. [ABSTRACT FROM AUTHOR]

Carbonylation of ethanol with CO2 as carbonyl source into value‐added esters is of considerable significance and interest, while remains of great challenge due to the harsh conditions for activation of inert CO2 in that the harsh conditions result in undesired activation of α‐C−H and even cleavage of C−C bond in ethanol to deteriorate the specific activation of O−H bond. Herein, we propose a photo‐thermal cooperative strategy for carbonylation of ethanol with CO2, in which CO2 is activated to reactive CO via photo‐catalysis with the assistance of *H from thermally‐catalyzed dissociation of alcoholic O−H bond. To achieve this proposal, an interfacial site and oxygen vacancy both abundant SrTiCuO3‐x supported Cu2O (Cu2O‐SrTiCuO3‐x) has been designed. A production of up to 320 μmol g−1 h−1 for ethyl formate with a selectivity of 85.6 % to targeted alcoholic O−H activation has been afforded in photo‐thermal assisted gas‐solid process under 3.29 W cm−1 of UV/Vis light irradiation (144 °C) and 0.2 MPa CO2. In the photo‐driven activation of CO2 and following carbonylation, CO2 activation energy decreases to 12.6 kJ mol−1, and the cleavage of alcoholic α‐C−H bond has been suppressed. [ABSTRACT FROM AUTHOR]

Carbonylation of ethanol with CO2 as carbonyl source into value‐added esters is of considerable significance and interest, while remains of great challenge due to the harsh conditions for activation of inert CO2 in that the harsh conditions result in undesired activation of α‐C−H and even cleavage of C−C bond in ethanol to deteriorate the specific activation of O−H bond. Herein, we propose a photo‐thermal cooperative strategy for carbonylation of ethanol with CO2, in which CO2 is activated to reactive CO via photo‐catalysis with the assistance of *H from thermally‐catalyzed dissociation of alcoholic O−H bond. To achieve this proposal, an interfacial site and oxygen vacancy both abundant SrTiCuO3‐x supported Cu2O (Cu2O‐SrTiCuO3‐x) has been designed. A production of up to 320 μmol g−1 h−1 for ethyl formate with a selectivity of 85.6 % to targeted alcoholic O−H activation has been afforded in photo‐thermal assisted gas‐solid process under 3.29 W cm−1 of UV/Vis light irradiation (144 °C) and 0.2 MPa CO2. In the photo‐driven activation of CO2 and following carbonylation, CO2 activation energy decreases to 12.6 kJ mol−1, and the cleavage of alcoholic α‐C−H bond has been suppressed. [ABSTRACT FROM AUTHOR]