Lin Huang,Xinhao Yu,Lei Huang,Xingtian Zhang,Li Gu,Yongyong Cao,Wei Li,Jing Hu,Xuebo Cao
With the development of the biodiesel industry, the annual production of the byproduct glycerol has increased to a level of nearly millions of tons. Efficient and clean utilization of glycerol is thus urgent and profitable. Direct glycerol fuel cells (DGFCs) capable of selective oxidation of glycerol and co-generation of electricity and high-value added chemicals seem to be the most compelling technique. Unfortunately, selective and durable electrocatalysts for fabricating DGFCs are still not available so far. Herein, ternary Pt–Pd–Ag alloy nanowires (NWs) are designed and synthesized under the direction of the d-band theory. The resulting Pd–Pt–Ag NWs exhibit significant activity towards the glycerol electro-oxidation reaction (GOR) and oxygen reduction reaction (ORR) in an alkaline medium, which outperforms the bimetallic Pt–Ag alloy NWs and the commercial Pt/C benchmark. Moreover, a homemade DGFC based on bifunctional Pd–Pt–Ag NW anode and cathode can achieve a peak power density of 13.7 mW cm−2 under ambient conditions (∼50% enhancement compared to the DGFC based on the Pt/C benchmark) and deliver a record voltage of 1.13 V ever reported in alcohol-feeding fuel cells. Besides the electricity profits, the DGFC concurrently generates value-added formate as a selective product of glycerol oxidization.
Haichao Zhou,Jianglin Liu,Dalang Chen,Yanlin Qin,Tiejun Wang,Xueqing Qiu,Xuliang Lin
The electrochemical conversion of glycerol into dihydroxyacetone (DHA) under mild conditions efficiently addresses glycerol surplus, enhancing its economic value. However, DHA production efficiency remains constrained by steric hindrance from secondary hydroxyl groups and sluggish glycerol electro-oxidation reaction (GOR) kinetics in weakly alkaline conditions. Herein, lignin-derived carbon-supported MnO–Ni heterojunction catalyst (MnO–Ni/C) is synthesized via self-assembly precipitation and in situ pyrolysis. The optimized MnO–Ni/C catalyst requires a low potential of 1.58 V to achieve 10 mA cm −2 , 270 mV lower than the oxygen evolution reaction (OER). It attains a 53.37% DHA selectivity with a high production rate of 864.75 mmol m −2 h −1 at 1.8 V. MnO–Ni/C heterostructures modulate the local electronic structure of Ni sites, optimizing glycerol adsorption configuration and enhancing selective adsorption of secondary hydroxyl groups and oxygen active species near the electrode surface. These synergistic effects significantly improve GOR kinetics and DHA production efficiency.