20.500.12556/RUL-160686 Scalable method for the preparation of Co$_x$Ni$_{1-x}$/alumina nanocomposites and their magnetic heating properties Magnetic nanocomposites with a high surface area matrix are attractive materials for novel catalyst supports. They can be remotely and selectively heated inside the reactor vessel when exposed to a high-frequency alternating magnetic field (AMF). These so-called "magnetic" or "cold" catalysts can revolutionize the chemical industry’s electrification, particularly for renewable energy applications such as hydrogen storage and release. In this study, we developed a scalable method for synthesizing magnetic Co$_x$Ni$_{1-x}$-Al$_2$O$_3$ nanocomposites. The synthesis is based on the co-precipitation of Co and Ni ions from an aqueous solution, coating the precipitated nanoparticles with a boehmite (AlOOH) shell via the in-situ hydrolysis of AlN powder and reduction at 850 °C in a flow of H$_2$. A combination of X-ray diffractometry (XRD) and scanning transmission electron microscopy (STEM/EDXS) showed the formation of nanocomposites containing globular Co$_x$Ni$_{1-x}$ nanoparticles (∼ 14 nm in size), homogenously distributed within the matrix composed of thin γ-Al$_2$O$_3$ nanosheets (∼ 30 nm wide and up to 3 nm thick), providing a high specific surface area (∼ 140 m$^2$ g$^{−1}$). The reduction process was studied using high-temperature XRD, hydrogen-temperature programmed reduction (H$_2$-TPR), and X-ray photoelectron spectroscopy (XPS). The magnetic properties were measured with a vibrating-sample magnetometer (VSM). The nanocomposites exhibited an excellent heating ability, exceeding 800 °C within a few minutes, even at relatively low AMF amplitudes (up to 58 mT) in a fixed-bed reactor. These results underscore the potential of Co$_x$Ni$_{1-x}$-Al$_2$O$_3$ nanocomposites for high-temperature catalytic processes, marking an advancement in magnetic catalyst support synthesis. CoNi alloy nanocomposite magnetic nanoparticles magnetic heating magnetic catalysis nanokompoziti magnetni nanonodelci magnetna kataliza zlitine nanostrukturni materiali true false true Angleški jezik Slovenski jezik Članek v reviji 2024-09-03 14:01:52 2024-09-03 14:01:53 2024-09-04 04:00:35 0000-00-00 00:00:00 2024 0 0 11 str. Vol. 1005, art. 176109 Nov. 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 621.7+621.9 1873-4669 10.1016/j.jallcom.2024.176109 205235459 1-s2.0-S0925838824026963-main.pdf 1-s2.0-S0925838824026963-main.pdf 1 772C1CF7E070D59DE4A88E4907400BEB 645640976734c874b4dbb2b7eb11b75d4aa5942c25941e9aff762a5437139c66 7bccf895-69ec-11ef-8f74-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=189454 https://www.sciencedirect.com/science/article/pii/S0925838824026963 0 1039887c-69ec-11ef-8f74-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=189453 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0