Mo[O.sub.3]/ironepinelium catalyst supported on ornamental rock residues with potential application in biodiesel production/Catalisador de mo[O.sub.3]/ferosepinelio suportado em residuos de rochas ornamentais com potencial aplicacao na producao de biodiesel

The search for environmentally correct fuels has been gaining momentum/prominence in scientific research, for example, using oils or fats of animal/vegetable origin and commercial/residual oils. These oils consist primarily of free fatty acids with high energy power and can be converted into fatty acid esters (biodiesel) using highly efficient and recyclable heterogeneous catalysts. Among the heterogeneous catalysts most used in the conversion of biodiesel, two are worth mentioning: Mo[O.sub.3] and ferrospinels. The first is because it contains in its structure, especially the orthorhombic, acidic active sites of Lewis and Bronsted-Lowry, and the second is because they have high specific surface areas and adequate magnetic characteristics that allow the recovery of the medium. Another interesting point is the use of residues for catalysis that has been highlighted, as they are materials that contain metals such as Fe, K, Si, Mg, Na, and Ti in their composition, which accelerate reactions. Thus, in this sense, this article proposes to carry out a bibliographical survey of the literature in experimental scientific papers and published reviews on the use of Mo[O.sub.3] and ferrospinels as heterogeneous catalysts supported on waste from cut ornamental rocks (granite/marble) for the production of biodiesel, which is the core of this search, on the online data platforms Science Direct (Elsevier) and Web of Science covering the period from 2016 to April 2023, using the Start software (State of the Art through Systematic Review). The results revealed a quantitative of 223 articles in general, in which 62 were accepted, and 161 were rejected. While in the review extraction stage, 22 papers were accepted, and 40 were rejected. In addition, the review revealed that most of the catalysts and catalytic supports used for the production of biodiesel with oils are oxides, nothing specifically informing the use of waste from cuts of ornamental rocks (granite/marble) as a host material (support) for the catalysts Mo[O.sub.3] and ferrospinels aiming the production of biodiesel. Therefore, meaning that it is not possible to use this type of residue as a support for catalysts, but rather that there may be a lack of research investigating this application.