Pt,Pd,Ni/MgO, Pt,Pd,Ni/Mg_0.97La³⁺_0.03O, Pt,Pd,Ni/Mg_0.93La³⁺_0.07O, and Pt,Pd,Ni/Mg_0.85La³⁺_0.15O (1% of each of the Ni, Pd, and Pt) catalysts were prepared by a surfactant-assisted co-precipitation method. Samples were characterized by the XRD, XPS, XRF, FT-IR, H₂-TPR, TEM, the Brunauer–Emmett–Teller (BET) method, and TGA and were tested for the dry reforming of methane (DRM). TEM and thermal gravimetric analysis (TGA) methods were used to analyze the carbon deposition on spent catalysts after 200 h at 900 °C. At a temperature of 900 °C and a 1:1 CH₄:CO₂ ratio, the tri-metallic Pt,Pd,Ni/Mg_0.85La³⁺_0.15O catalyst with a lanthanum promoter showed a higher conversion of CH₄ (85.01%) and CO₂ (98.97%) compared to the Ni,Pd,Pt/MgO catalysts in the whole temperature range. The selectivity of H₂/CO decreased in the following order: Pt,Pd,Ni/Mg_0.85La³⁺_0.15O > Pt,Pd,Ni/Mg_0.93La³⁺_0.07O > Pt,Pd,Ni/Mg_0.97La³⁺_0.03O > Ni,Pd,Pt/MgO. The results indicated that among the catalysts, the Pt,Pd,Ni/Mg_0.85La₂³⁺_0.15O catalyst exhibited the highest activity, making it the most suitable for the dry reforming of methane reaction.

In the present study, a Co–Ni–Pd/CaO _0.85 ZrO _0.15 trimetallic nanocomposite was synthesized and characterized using Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and transmission electron microscopy (TEM) to characterize its structural and morphological properties. The antibacterial activity of the synthesized nanocomposite was also evaluated against selected gram- positive and gram-negative bacterial strains. The results of FTIR confirmed the formation of acetylacetonate ligands and metal–oxygen bonds in the nanocomposite. XRD patterns confirmed the crystalline structure with identified diffraction peaks of cubic CaO and ZrO ₂ phases. TEM images showed agglomerated nanoparticles with sizes ranging from 45 to 85 nm. The novelty of this study focuses on the incorporation of Co, Ni, and Pd into the CaO–ZrO ₂ matrix, which leads to the generation of multiple active surface sites and enhances synergistic interactions, thereby improving the antibacterial performance. The antibacterial activity of the prepared nanocomposite was assessed against gram-positive and gram-negative bacteria. Increased inhibition zones were noted at higher concentrations, recorded 9.80 mm for Staphylococcus lentus , 9.73 mm for Bacillus subtilis , 11.33 mm for Pseudomonas aeruginosa , and 11.65 mm for Escherichia coli at 10 000 ppm. The nanocomposite showed higher antibacterial activity against gram-negative bacteria ( P. aeruginosa and E. coli ) than the gram-positive one ( Staphylococcus lentus and Bacillus subtilis ). These results provide a preliminary indication of the antibacterial potential of the nanocomposite, particularly against gram-negative bacteria. Nevertheless, further biological studies are necessary to comprehensively evaluate and confirm its antibacterial efficiency.