Solar generated hydrogen from an optimized P25 thin film of 3.2 mg/cm 2 with 0.25% of platinum as co-catalyst improves the peak power output of a methanol microfluidic fuel cell operated with a methanol to water ratio of 1:1 almost ninefold, from 22 mW/cm 2 to 213 mW/cm 2 . Different methanol to water ratios in the fuel tank generate similar amounts of hydrogen, but the cell performance has large variations due to the different oxidation kinetics of hydrogen and methanol in the fuel breathing anode, resulting in a mixed-potential anodic performance. The trade-off between power output and fuel utilization diminishes in this system. The methanol utilization efficiency at peak power operation increases from 50% (for 0.2 V) to 78% (for 0.5 V) for methanol to water ratio of 1:1. The result indicates that in-situ generation of hydrogen by solar light can be applied to both portable and large-scale stationary fuel cells.
Jinfu Ma,Xiangyu Gao,Dewei Wang,Tong Xue,Shaolin Yang
The fuel discharging efficiency of direct borohydride fuel cell (DBFC) depends on both the anodic catalyst activity and borohydride hydrolysis. In this paper, Co 3 O 4 anodic catalysts prepared from different cobalt sources used in DBFC have been investigated. It showed that the catalytic performance of Co 3 O 4 was associated with its microstructure that relied on the precursor. The maximum power densities obtained was 40, 62 and 28 mW cm −2 of DBFC with Co 3 O 4 catalyzed anode from CoCl 2 (marked DBFC-A), Co(NO 3 ) 2 (marked DBFC-B) and Co(CH 3 COO) 2 (marked DBFC-C), respectively. The Co 3 O 4 -A has the highest number of electron transfer ( n = 7.06 ) which is close to the theoretical value ( n = 8 ), and DBFC-A showed good voltage stability with specific capacity of 720 mAh.g −1 . A rapid voltage attenuation occurred in DBFC-B with the specific capacity of 330 mAh.g −1 because Co 3 O 4 from Co(NO 3 ) 2 has the higher catalytic activity for both borohydride oxidation reaction (BOR) and hydrolysis which lead to the lower fuel utilization efficiency.
Lin Li,Tingting Han,Yuxi Wu,Jiahao Cheng,Penghui Yao,Fangyong Yu,Jinjin Zhang,Wei Zeng,Naitao Yang,Yongdan Li
Direct carbon solid oxide fuel cells (DC-SOFCs) demonstrate significant promise in clean energy conversion technology due to their direct utilization of solid carbon, high-temperature operation, and fuel flexibility. Exploring biomass as a fuel for DC-SOFCs is particularly intriguing within this context. Here, we successfully developed the biochar derived from tomato straw and conducted a comprehensive physicochemical characterization to investigate its feasibility and advantages for DC-SOFCs. Electrochemical results revealed that DC-SOFC powered by tomato straw biochar achieved an impressive output of 219 mW cm −2 at 850 °C, surpassing the cell output of 187 mW cm −2 operating on commercial activated carbon. Furthermore, the single cell demonstrated a higher discharge plateau and a longer lifetime of 26.5 h under 50 mA at 850 °C. Consequently, fuel utilization was calculated to be up to 29.7%, which was also superior to that of activated carbon-fueled DC-SOFC, further validating the effectiveness of tomato straw biochar in improving DC-SOFC performance. These outstanding performances were primarily attributed to the unique porous microstructure, naturally existing metal elements, high disorder and large specific surface area of the biochar, which effectively promoted the reverse Boudouard reaction to produce a substantial amount of CO for anode reaction, thus enhancing the DC-SOFC performance and efficiency. These findings underscore the enormous application potential of tomato straw biochar for DC-SOFCs, providing strong support for advancing clean energy technology and achieving carbon neutrality goals.
危险品化学品经营许可证（带存储）