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Activated carbon (AC) supported catalysts have been extensively applied as deoxygenation (DO) catalysts. However, the details of in situ experimental investigations that relevant to this catalyst are limited. Hereby, we present a series of operando/in situ spectroscopic experiments for DO of waste sludge palm oil (WSPO) by using atomically dispersed La-W bimetallic supported AC catalysts (La-W/AC) with well-defined structures. The La(5%)-W(2%)/AC catalyst prepared through co-precipitation (CP) process rendered high surface area (741 m2/g) and catalyst’s acidity (13319.16 µmol/g). Besides, the catalyst demonstrated a superior catalytic performance of DO reactivity under optimal reaction conditions of 0.5 % catalyst loading (CL), a one hour reaction time (Rt), and 250 °C reaction temperature (RT), achieving 98 % WSPO conversion to green fuel turnover frequency (TOF) of 0.0153 s-1. The reusability of La(5%)-W(2%)/AC catalyst was positively active for eight runs of DO process with constant of conversion rate at > 87 %. In addition, DO mechanism was of WSPO model compound (palmitic acid) was conducted to gain the clearer insight of reaction pathway catalysed by La-W/C catalyst. In situ FTIR analysis confirms the presence of intermediates (e.g. n-heptadecane, n-pentadecane, n-nonane, n-tridecane, and trimethylcyclopentene) that attributed buy the acid site of the heteropoly acid support. Besides, in situ XAS spectroscopy consolidates the oxidation state of La and W, where the presence of metal centre, support and substrate were confirmed to reflect the occurrence of palmitic acid DO on atomically dispersed La and W active sites. Thus, the present findings identified several key product intermediates during DO process, as well as the stable-state of catalyst structure, which suggest that the atomically dispersed La(5%)-W(2%)/AC catalysed reactions follow an unconventional decarboxylation/decarbonylation reaction pathways with the activation of oxygen (O2) removing is rate limiting.

Hydrogen production using polymer membrane electrolyzers is an effective and valuable way of generating an environmentally friendly energy source. Hydrogen and oxygen generated by electrolyzers can power drone fuel cells. The thermodynamic analysis of polymer membrane electrolyzers to identify key losses and optimize their performance is fundamental and necessary. In this article, the process of the electrolysis of water by a polymer membrane electrolyzer in combination with a concentrated solar system in order to generate power and hydrogen was studied, and the effect of radiation intensity, current density, and other functional variables on the hydrogen production was investigated. It was shown that with an increasing current density, the voltage generation of the electrolyzer increased, and the energy efficiency and exergy of the electrolyzer decreased. Additionally, as the temperature rose, the pressure dropped, the thickness of the Nafion membrane increased, the voltage decreased, and the electrolyzer performed better. By increasing the intensity of the incoming radiation from 125 W/m2 to 320 W/m2, the hydrogen production increased by 111%, and the energy efficiency and exergy of the electrolyzer both decreased by 14% due to the higher ratio of input electric current to output hydrogen. Finally, machine-learning-based predictions were conducted to forecast the energy efficiency, exergy efficiency, voltage, and hydrogen production rate in different scenarios. The results proved to be very accurate compared to the analytical results. Hyperparameter tuning was utilized to adjust the model parameters, and the models’ results showed an MAE lower than 1.98% and an R2 higher than 0.98.