such as high specific surface areas (SSA), ultra low density, and electric conductivity. Additionally, the synthesis of these materials allows the control over the morphology and gives the possibility of building up hybrid materials. These features make them promising materials in emergent fields of applications, such as energy storage, [1, 2] electrocatalysis, [3] desalination, [4] bio-sensing, [5] and gasification gas cleaning. [6] Synthesis of carbon aerogel from biopolymers (e.g.,

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... offers important advantages, since biomasses are inexpensive, biocompatible, abundant, and rich in functional groups (e.g., -OH,-C(O) OH, -NH 2 ). Furthermore, by means of its synthesis process (dissolution, gelation, and subsequent carbonization), carbon materials with a good balance in its electrochemical properties (i.e., energy and power density) can be achieved. [7] Another important advantage of carbon aerogels is their doping capacity. Carbon aerogels doped with various materials such as heteroatoms, nanocarbon, transition metals, and noble metals have been reported to extend their potential in different electrochemical applications. [5, 8, 9] Metal-doped organic or carbon aerogels can easily be prepared via the addition of the metal precursor to the initial mixture, ion-exchange, or reduction of the metal precursor on the organic or the carbon aerogel. However, the retention of the textural properties, the homogeneous distribution, and the anchoring of the metallic domains are still challenging. [9, 10] Noble metals in carbon-based materials have been intensively investigated and found to be promising additives of electrode materials for supercapacitors. They can improve the specific capacitance, conductivity, as well as the chemical and thermal stability of the electrode materials. [11] Several carbon materials, such as single walled carbon nanotube, [12] graphene hydrogel, [13] carbon nano-onions, [14] multi-walled carbon nanotube (MWCNT), [15] and reduced graphene oxide [16] have shown an enhancement between 200% and 600% in their specific capacitances by means of doping with Ag, Au, or Pt. Palladium is of great interest as dopant due to its high affinity for hydrogen and catalytic activity, [17] besides it is the most abundant noble metal on the Earth and therefore the least expensive among them. Consequently, it has been widely evaluated as an additive in carbonaceous materials [18] for catalysis [19] [20] [21] [22] [23] and hydrogen storage. [24] Pd nanoparticles (PdNPs) have also been assessed as active catalyst material in LiO 2 batteries, In order to implement a sustainable approach in the development of carbonaceous materials with improved capacitive properties, the development of Pddoped 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.