In order to implement a sustainable approach in the development of carbonaceous materials with improved capacitive properties, the development of Pd‐doped cellulose carbon aerogels (CA‐PdX) is presented. Upon introducing Pd nanoparticles to the carbonaceous matrix prior to the gel formation, carbon aerogels with various Pd content are prepared. Physicochemical properties (such as texture, morphology, crystal structure, and surface chemistry) of CA‐PdX are revealed. Additionally, a comparative analysis in their electrochemical properties is performed to shed light on the effect of Pd incorporated into the matrices. It is found that Pd‐doping leads to the significant enhancement of power and energy densities (2.9‐fold and 55‐fold, respectively) compared to those of carbon aerogel without doping (CA‐Blank). The straightforward preparation method as well as the powerful control over the structure and composition pave the way toward the utilization of these hybrid materials in energy storage applications.

Olive mill waste (OMW) is a solid residue largely generated in the production of olive oil, whose haphazard dumping causes soil and water contamination due to its high content of organic compounds and characteristic acidic nature. This agroindustrial waste source can be used as a potential sustainable precursor for the production of activated carbon that can be used as an outstanding sorbent for CO₂ capture. In this work, OMW was utilized as the activated carbon precursor, and KOH was used as the activating agent. Activation temperature, time, and KOH/carbon ratio were investigated in order to produce suitable activated carbons for CO₂ capture. Textural and chemical characterizations were made by scanning electron microscopy (SEM), adsorption–desorption N₂ isotherms at 77K and CO₂ isotherms at 273 K, and Fourier transform infrared spectroscopy (FTIR). CO₂ adsorption isotherms between 0 and 6 bar at 25 °C were obtained, and CO₂ uptake was also measured at 30 °C in 100 mL/min of 15% vol CO₂ for 180 min. The adsorption kinetic curves were fitted with pseudo-first-order (PFO) and pseudo-second-order (PSO) models. Also, the cyclic performance of the best adsorbent was explored for 10 adsorption/desorption cycles. The highest CO₂ uptake was observed for the activated carbon synthesized with a KOH/precursor ratio of 2:1 and activated at 650 °C for 45 min, which had a CO₂ uptake of 105.7 mg/g (2.4 mmol/g) in pure CO₂ and 37.2 mg/g (0.84 mmol/g) in 15% vol CO₂, as measured in a TGA at 30 °C.