Amphiphilic nanomaterials interact with water/oil interfaces, catalyzing reactions in the In-Situ Combustion (ISC) process. This work aims to compare the surface modification of different crystalline phases of MnO2 in the two most relevant processes involved in ISC: transportation and catalysis, by evaluating the stability of nanofluids and their catalytic activity regarding the oxidation of asphaltenes.α-, β-, γ-, and δ-MnO2 crystalline phases of manganese dioxide were synthesized by a hydrothermal method and later functionalized either with (APTES) (3-Aminopropyl)triethoxysilane) or citric acid (CA) through a Pickering Emulsion route. The physicochemical properties of these nanomaterials were studied using TEM, IR spectroscopy, XRD, DSC, static contact angle, Z-potential and the results suggest a Janus character upon a suitable functionalization for all cases.Citric acid functionalized nanomaterials showed higher stability to promote aqueous suspensions due to the hydrophilic nature of the organic agent and the possibility of interaction through H-bonds with water molecules. Nevertheless, they show a lower catalytic activity regarding the oxidation of asphaltenes when compared to the materials functionalized with APTES. Therefore, chemical functionality must be considered in both transportation and combustion stages of in-situ combustion process to fabricate a suitable nanocatalyst.