The ability to use polypropylene and polyamide fibers modified with a cobalt phthalocyanine complex as catalysts for removing mercaptans was evaluated. Fibers were prepared by electrospinning from polymer solutions and melts. The average diameter and specific surface area were determined. The fiber surface was activated by treatment with a low-temperature plasma in air. The catalytic activity and specific capacity of the fibers before and after plasma treatment were calculated. Polymeric fibers can be produced by several methods. The traditional method is extrusion. At present, electrospinning, which is the spinning of ultrafine fibers from a liquid medium in an electrical field, is especially interesting. This method is typified by simplicity, high throughput, and low polymer consumption and can produce finished material in one step. Electrospinning is the most efficient method for preparing continuous polymeric fibers with improved mechanical properties and diameters from several nanometers to several micrometers. Fibers prepared by electrospinning are used in medicine, bioengineering, and filtration of gases and liquids; in the fabrication of composites (for reinforcing polymeric matrices); and for other applications [1, 2]. Nano-sized fibers are used in catalysis because of their large specific surface area, low polymer consumption, and cost savings in addition to the ability to produce continuous fibers. Herein we examine the possibility of using polypropylene (PP) and polyamide (PA) fibers modified by a cobalt phthalocyanine complex (CoPc) as catalysts for removing mercaptans. In the initial stage of the work, we prepared heterogeneous catalysts of PP and PA fibers modified with CoPc. PP fibers were spun from polymer melt; PA, from a 12% solution of PA-6.6 in formic acid. The modification was made by dissolving CoPc in the polymeric matrix during fiber spinning. The catalyst content in PP fibers was 5 and 10%; in PA fibers, 10, 20, and 30%. The mass of the studied fiber samples was 0.0064 g. The specific surface area of the samples was determined by low-temperature adsorption (desorption) of argon on a Tsvet 211 sorption meter. The PP fiber diameter was measured using a Hitachi S-3000N scanning electron microscope with an Edwards Sputter Coater S 150B attachment for coating samples with a layer of gold for better contact. The PA fiber diameter was measured using a Solver 47 PRO atomic force microscope. Catalyst efficiency was estimated with an accuracy of ±5% from the reduction of propylmercaptan content resulting from stirring its alkaline aqueous solution of concentration 0.92% (by mass). The experimental temperature was 25°C. The content of dissolved oxygen in the initial sodium propylmercaptide solution was determined using a portable series HQ meter with an IntelliCAL TM sensor. A blank experiment was carried out in parallel and consisted of stirring an alkaline aqueous solution of propylmercaptan without catalyst. The total duration of the experiment was 20 min. Samples were taken every 5 min. Potentiometric titration was used to determine the concentration of mercaptide sulfur remaining in the solution [3]. Samples were rinsed after performing each sequential mercaptan removal step.