Search

Although clean energy generation utilizing the Oxygen Reduction Reaction (ORR) can be considered a promising strategy, this approach remains challenging by the dependence on high loadings of noble metals, mainly Platinum (Pt). Therefore, efforts have been directed to develop new and efficient electrocatalysts that could decrease the Pt content (e.g., by nanotechnology tools or alloying) or replace them completely in these systems. The present investigation shows that high catalytic activity can be reached towards the ORR by employing 1.8 ± 0.7 nm Ir nanoparticles (NPs) deposited onto MnO

The influence of calcination temperatures on the physical-chemical properties and catalytic performance of MoO3 catalysts, synthesized using a hydrothermal approach, was studied. We present herein a catalyst calcined at 600 °C able to convert buriti, babassu, soybean, pequi, macauba, and waste cooking oils into biodiesel with yields over 90% under optimized conditions. In addition, the catalyst was used up to 8 times without significant performance loss and without the need for washing between one run and another. We also found out that a very small catalyst concentration (0.50%) was necessary for best results. The materials that underwent high calcination temperatures were characterized by TG, FT-IR, BET, adsorption-desorption isotherms and X-ray diffraction.

The addition of antioxidants to biodiesel, as well as the elimination of conditions favoring the initiation of the oxidation reaction, can inhibit or retard the oxidative process. In this work, we present a comparative study of the antioxidant activity of extracts of bilberry (BE), oregano (EO), and basil (BAE), quercetin (QC) and pyrogallol (PY) in biodiesel derived from soybean oil. The oxidation stability of the samples was studied using the Rancimat and PetroOXY methods under 90, 100, 110, 120, 130 and 140 °C. Among the extracts, the highest total phenolic contents were found in the oregano extract, followed by the basil and bilberry extracts. The apparent activation energy for the consumption of the antioxidants was determined by the Arrhenius equation. The substrates were ranked in the descending order of PY (81.39 kJ mol −1 ) > QC (77.73 kJ/mol) > BE (63.85 kJ/mol) > BAE (62.02 kJ/mol) > OE (52.04 kJ/mol) for the Rancimat method and PY (79.64 kJ/mol) > QC (68.92 kJ/mol) > BE (45.31 kJ/mol) > OE (44.48 kJ/mol) > BAE (41.98 kJ/mol) for the PetroOXY method. Parameters such as enthalpy, entropy, and Gibbs free energy indicated a non-spontaneous endothermic process, as expected for antioxidant samples. The shelf-life of the samples was predicted as: PY > QC > BE > BAE > OE and PY > QC > OE > BE > BAE for Rancimat and PetroOXY methods, respectively. Considering the sensibility and the analysis time, both methods meet the necessary requirements for the stability evaluation of biodiesel samples.

A catalyst comprised of SnO2 impregnated on ZnO nanowires, which presented remarkable ability to catalyze fatty acid esterification/transesterification reactions, is reported. For optimization of reaction conditions, artificially acidified soybean oil with 10 wt.% oleic acid was used as a model feed. The optimized conditions were: 150 °C, 6 h, 5 g of oil, catalyst concentration of 5%, and methanol:oil molar ratio of 15:1. The catalyst achieved 92% of total fatty acid methyl esters (FAME) content and was used five times without the necessity of catalyst washing from one reaction to the other. Then, such conditions were applied to produce biodiesel from the oil extracted from Scenedesmus sp. microalgae; the system reached 72% of FAME content, without any previous refining or degumming process of the oil. Rietveld refinement, X-ray diffraction, elemental mapping in scanning transmission electron microscopy, X-ray photoelectron spectroscopy, and pyridine-desorption Fourier-transform infrared spectroscopy were used to characterize the material.

Antibiotics in water bodies have raised global concerns due to the risk of developing drug-resistant bacteria stains. Thus, the occurrence of macrolide antibiotic residues in environmental waters has attracted significant attention lately. Herein, a composite material comprised of Super P carbon black particles and chitosan was developed as an electrochemical sensor to determine macrolide antibiotics, including erythromycin, azithromycin, clarithromycin, and roxithromycin. The electrode was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy, and Raman spectroscopy. The proposed sensor coupled to a batch injection analysis system proved to be rapid (125 injections h−1), reproducible (RSD = 2.60%), and present a wide linear range (1.0–190.0 µmol L−1). Also, it was successfully applied for the direct determination of the four macrolide antibiotics in water and pharmaceutical samples. Recovery tests were performed on both samples, in which recovery values between 96.0% and 104.7% were achieved for tests performed on environmental samples, and between 95.6% and 105.1% for tests performed on pharmaceutical samples, proving the excellent accuracy of the system. Based on electrochemical/physicochemical characterizations and sensing performance, the applicability of this material was demonstrated as an attractive alternative for use in routine analysis from economic and portability points of view.

We have prepared, by a sol-immobilization method, bimetallic catalysts with different Au:Pt atomic ratios supported on commercial SrCO3. The catalytic performance for the oxidation reaction of benzyl alcohol of such materials was compared to the monometallic counterparts, aiming at the obtaining of the best composition of the material. It was found that the Au:Pt atomic ratio presents a remarkable effect on the system performance, i.e., Pt-rich systems are more selective; however, less active. Thus, an equilibrium related to the activity and selectivity of the system was obtained by considering the yield of the system. Also, some density functional theory (DFT) insights were obtained by using a cluster of 14 atoms of Au and 1 or 2 atoms of Pt. X-ray photoelectron spectroscopy, elemental mapping in scanning transmission electron microscopy before and after catalyst usage, flame atomic absorption spectroscopy, Rietveld refinement, among other techniques, were used and associated to the experimental data, which allowed us to propose a catalytic mechanism for the system, which was important since SrCO3 has not been considered before as catalyst support for alcohol oxidation reactions.

AuPd nanoparticles have gained substantial attention due to their application in selective oxidation of alcohols. However, due to the radical nature of the oxidation of benzyl alcohol, under specific conditions, even without a catalyst, the reaction occurs and affects the selectivity of the system. Therefore, we aimed to develop a catalyst that enables the control of the oxidation leading to higher reaction selectivity. To accomplish this, we have prepared a catalytic support comprised of CoFe2O4 nanoparticles impregnated with Sr(OH)2 that presented a significant control of the reaction selectivity without any metal or external base addition. After the impregnation of AuPd nanoparticles in a specific ratio, the reaction reached a selectivity of > 99% for benzaldehyde, in 3.5 h, with a recycle regime of five runs without loss of activity and selectivity. Our results show that the judicious choice of the ratio of the metals prevents the necessity of manipulating the reaction conditions to improve the performance of the system. Additionally, studies under N2 and O2 environments, with or without water, confirmed the role of the O2 in the system. Holding all this information, we propose a possible mechanism for the prepared system.

The development of stable and active TiO2 nanotubes (NTs) decorated with plasmonic gold nanoparticles (Au NPs) represents a strategy for charge-transfer processes improvements. However, organic capping ligands used for Au NPs synthesis usually remain on the surface of the metal, leading to poor Schottky junctions between Au and TiO2. Herein, we report on the synthesis of a nanotubular matrix of TiO2 decorated with gold without the need of ligands. The Au NPs mean diameter (12 nm) was similar to all the samples prepared, no matter the metal loading. Such materials enabled to use the metal as a cocatalyst for photogeneration of H2under UV and visible light irradiations. We found an optimum metal loading (2.6 wt% Au) that enabled an improvement of 760% on the H2 production when compared to the bare TiO2 NTs under UV-Vis irradiation. In addition, such catalyst was able to perform photogeneration of H2 under visible irradiation, which was not conceivable before the metal immobilization over the TiO2 NTs. The yield obtained was comparable to the observed when the catalyst was used under UV-Vis conditions. The produced materials were fully characterized by UV-Vis, XRD, TEM, and SEM.

We reported the organic template-free synthesis of gold (Au) nanoparticles (NPs) supported on TiO2, SiO2, and Al2O3 displaying uniform Au sizes and high dispersions over the supports. The Au-based catalysts were prepared by a deposition–precipitation method using urea as the precipitating agent. In the next step, the solvent-free oxidation of benzyl alcohol was investigated as model reaction using only 0.08–0.05 mol% of Au loadings and oxygen (O2) as the oxidant. Very high catalytic performances (TOF up to 443,624 h−1) could be achieved. Specifically, we investigated their catalytic activities, selectivity, and stabilities as well as the role of metal–support interactions over the performances. The conversion of the substrate was found to be associated with the nature of the employed support as the Au NPs presented similar sizes in all materials. A sub-stoichiometric amount of base was sufficient for the catalyst activation and the observation of the catalysts profile over the time enable insights on their recyclability performances. We believe this reported method represents a facile approach for the synthesis of uniform Au-supported catalysts displaying high performances.

Gold nanoparticles have shown excellent activity for selective oxidation of alcohols; such catalytic systems are highly dependent on the initial activation of the substrates, which must occur on the catalyst surface in heterogeneous catalysts. In many cases, an extra base addition is required, although the basicity of the support may also be of significant importance. Here, we explored the intrinsic basicity of magnesium-based enrichments on CoFe2O4 magnetic nanoparticles for the oxidation of benzyl alcohol using molecular oxygen as oxidant. The MgO and Mg(OH)2 enrichments enabled gold impregnation, which was not possible on the bare CoFe2O4 nanoparticles. The Au/MgO/CoFe2O4 and Au/Mg(OH)2/CoFe2O4 catalysts reached 42% and 18% conversion, respectively without base promotion, in 2.5 hour and 2 bar of O2. When the catalysts were tested with sub-stoichiometric amounts of base, they became more active (>70% of conversion) and stable in successive recycling experiments without metal leaching, under the same reaction conditions. We also showed the oxide phases of the enrichments performed using Rietveld refinements and how the Mg(OH)2 phase interferes with the activity of MgO-based materials.

The synthesis of efficient and reusable gold-based catalysts for the selective oxidation of alcohols is a strategy for the development of green processes. Pre-formed nanoparticles syntheses are an easy way to produce controlled-nanosized gold materials; however, the selection of a support is not trivial. Herein, we proposed a CoFe2O4 support enriched with Sr(OH)2, which holds remarkable properties and is suitable for the synthesis of a stable gold-based catalyst for the oxidation of benzyl alcohol. We suggested that the interaction between the CoFe2O4 and the Sr(OH)2 is highly important for the performance of the catalyst. Under the base-free condition of 2.5 h, 100 oC and 2 bar of O2, the catalyst reached 58% of conversion with 76% of selectivity to benzaldehyde. With K2CO3 addition, the conversion and selectivity to benzaldehyde increased to 87% and 88%, respectively. Any gold leaching was detected in 5 successive runs, attesting the noticeable stability that the catalyst presents. This work provides great potential for the selective oxidation of alcohols with high activity since the magnetic properties of the catalyst provide an easy route and allows the separation of the medium reaction. In addition, we are here proposing an important interaction between the Sr(OH)2 and the magnetic nanoparticles.

Pt-based cathodes in direct methanol fuel cells are promising materials for a wide range of applications. However, such materials suffer significant performance loss due to severe methanol crossover from anode to cathode, resulting in mixed potentials from methanol oxidation and oxygen reduction reaction. Herein, we proposed some facile synthesis procedures to avoid Pt active sites contamination from methanol. The strategy was to associate controlled ultrasmall Pt nanoparticles (NPs), Vulcan XC-72, and MnOx species prepared from Mn(NO3)2.4H2O. Interestingly, we have observed that depending on the synthetic pathway chosen, the methanol-tolerance ability of the material increased, suggesting different interactions among the components of the catalyst. The results indicated an improved selectivity of the system due to a synergy between Pt and MnOx. The best strategy was the immobilization of ultrasmall Pt NPs (~2 nm) on carbon black, before impregnation and thermal decomposition of MnOx, which almost wholly suppressed the methanol oxidation interference on the system. Also, the optimized cathode presented a comparable performance for ORR to the traditional Pt/C without methanol addition. To further rationalize such findings, physical and electrochemical characterizations were successfully performed, which allowed us to better understand the proposed catalysts and their different methanol-tolerance abilities.

We present the design of a hydroformylation catalyst through the immobilization of air-stable Rh nanoparticles (NPs) on a magnetic support functionalized with a hyperbranched polymer that bears terminal phosphine groups. The catalyst modification with the hyperbranched polymer improved the metal–support interaction, the metal loading, and the catalytic activity. The catalyst was active for the hydroformylation of natural products, such as estragole, and could be used in successive reactions with negligible metal leaching. The phosphine grafting played a key role in the recyclability of Rh NPs under hydroformylation conditions. The catalytic activity was maintained in successive reactions, even if the catalyst was exposed to air during each recovery procedure. The modification of the support with hyperbranched polyester allowed us either to increase the number of Rh active species or to obtain more active Rh species on the catalyst surface.

Gold nanoparticles have shown excellent catalytic properties in selective oxidation of alcohols in the presence of base; however, the influence of the nature and concentration of the base on gold catalyst activity and selectivity is not completely understood. We here present a study of the effect of using weak and strong bases on the conversion and selectivity of PVA-stabilized gold nanoparticles supported on titania (AuPVA/TiO2) for benzyl alcohol oxidation. The increase in the concentration of base had little effect on conversion when a weak base was used (K2CO3, Na2B4O7 and Na(CH3COO)), due to the buffer effect, but strongly affected selectivity. The bases with higher pKa values provided higher conversions and increased production of benzoic acid. For the strong base NaOH, benzoic acid was always the major product, although conversion decreases in excess of base. The formation of benzoic acid is avoided by using K2CO3 in non-aqueous media; benzaldehyde is the main product in cyclohexane whereas benzyl benzoate is also formed in significant amounts in solvent-free conditions. The promotion effect observed in the presence of base was discussed in terms of reaction mechanism.

Metal nanoparticles have received intense scientific attention in the field of catalysis. Precise engineering of nanomaterials’ size, shape and surface composition, including adsorbed capping ligands, is of utmost importance to control activity and selectivity, and distinguish colloidally prepared metal nanoparticle catalysts from traditional heterogeneous catalysts. The interface between the material and the reaction medium is where the key interactions occur; therefore, catalysis occurs under the influence of capping ligands. In this Perspective review, we focus on the choice of capping ligands (or stabilizing agents), and their role and fate in different steps from preparation to catalysis. Evaluating the influence of the ligands on the catalytic response is not trivial, but the literature provides examples where the ligands adsorbed on the nanoparticle surface dramatically change the activity and selectivity for a particular reaction, while acting either as a dynamic shell or a passivation coating. Steric and electronic effects resulting from the presence of adsorbed ligands have been proposed to influence the catalytic properties. Attempts to remove the capping ligands are discussed, even though they are not always successful or even necessary. Finally, we outline our personal understanding and perspectives on the use of ligands or functionalized supports to tune the activity and selectivity of supported metal nanoparticles.

The development of stable and active gold catalysts has arisen as a significant strategy for oxidation of alcohols. Nano-size PVA-stabilized gold nanoparticles immobilized on Sr(OH)2 by colloidal deposition presented high catalytic activity for benzyl alcohol oxidation. In 2.5 h, 2 bar of O2 and without extra-base addition, the calcined support reached 54.6% (100 °C) and 67.4% (140 °C) of conversion, presenting the remarkable and unexplored intrinsic basicity that strontium-based materials retain. With sub-stoichiometric K2CO3 adding, under the same catalytic conditions, the catalyst conducted the reaction with similar activity, but with excellent reusability in the process, without any gold leaching. We investigated the influence that the support synthesis method and the solvent used for the NPs stabilization have on the oxidation activity. The produced materials were fully characterized by XPS, Rietveld refinement, and TEM.

Biodiesel production has gained a lot of attention due to its environmental benefits and production from renewable sources. Here, it is reported a magnetically recoverable catalyst of SrO immobilized on a CoFe2O4 support (SrO/CoFe2O4), which was efficiently applied for babassu oil transesterification and used up to four cycles without a significant activity loss. The stability and performance of the catalyst were analyzed considering the solvent used for its synthesis. Characterizations such as vibrating sample magnetometer (VSM), thermogravimetry (TG), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) were performed. The present study demonstrated that the catalyst has a strong magnetic response, which reflects the nature of the nanoparticles. For the first run, the material presented a yield of 96% when synthesized in acetone in a molar proportion of SrO/CoFe2O4 of 5:1.

Microalgae lipid-derived biofuels is considered promising candidates for substitution of petroleum-based energy sources. However, the lipid extraction from the algal biomass stands as a challenge due to its low yields and cost-intensive cell disruption procedures. In this study a multivariate optimization of the extraction conditions was suggested, aiming a maximization of the lipid extraction from Scenedesmus sp. microalgae grown using wastewater as a nutrient medium. The extraction method, extraction time, solvent mixture and pretreatment were considered between upper and lower levels in order to access their significance, including their interactions, on the experimental response, while using a reduced number of experiments. The studies were performed using low-cost extraction methods (magnetic stirring and ultrasonication). The optimal extraction condition was obtained using CHCl3:MeOH (2:1) solvent mixture, in a 2-hour extraction period using ultrasonication. Fatty acid profiles of extracted lipids were also evaluated.

Gold nanoparticles have shown excellent activity for selective oxidation of alcohols; such catalytic systems are highly dependent on the initial activation of the substrates, which must occur on the catalyst surface in heterogeneous catalysts. In many cases, an extra base addition is required, although the basicity of the support may also be of significant importance. Here, we explored the intrinsic basicity of magnesium-based enrichments on CoFe

The presence of capping ligands on the surface of metal nanoparticles (NPs) has been recognized to be a key factor for the control of their size and shape as well as for their stabilization, but their influence on the NP behavior in catalysis is far from being well-understood. Here, we investigated the performance of Rh NPs stabilized by tetraoctylammonium bromide (Rh-TOAB NPs) when applied as precatalyst for hydroformylation reaction. An ehnancement of the catalytic activity was clearly observed after adding monophosphines as a reaction modifier. More interestingly, a much higher effect was observed when a phosphine was directly used as capping ligand for the synthesis of the Rh particles, i.e . in the absence of TOAB. Indeed, triphenylphosphine-stabilized Rh NPs (Rh-PPh 3 NPs) were found to be a unique precursor for hydroformylation active catalytic species, leading to higher activity attributed to the existence of a strong phosphine-rhodium interaction in this case. The Rh-PPh 3 NPs appeared less affected when adding poisoning ligands in catalytic reaction than the Rh-TOAB NPs PPh 3 system which deactivates in the presence of CS 2 . In addition, a large excess (20 equiv. per Rh atom) of PPh 3 was necessary to activate the Rh-TOAB NPs, similarly to the amount typically used in homogeneous catalytic systems. In the contrary, one equiv. of PPh 3 (per Rh atom) was enough to prepare Rh-PPh 3 NPs, which are more active and more stable against CS 2 poisoning. All together our results evidence that a direct interaction of PPh 3 ligand at the surface of Rh NPs plays an important role on their behavior in hydroformylation catalysis.

We report the preparation of rhodium nanoparticles (NPs) stabilized by 1-octadecanethiol (ODT), polyvinyl alcohol (PVA), and tetraoctylammonium bromide (TOAB), and their application for hydrogenation catalysis. The three metal–ligand systems correspond to different mechanism of NPs stabilization via strong covalent linkage, chemisorbed atoms and electrostatic interactions, respectively. We found a strong effect of the interaction between the stabilizer and the surface of the metal nanoparticle on the catalytic activity. The Rh NPs were studied as soluble nanoparticle catalysts and as precursors for the synthesis of supported catalysts. All catalysts were tested in the hydrogenation of cyclohexene under similar conditions as a model reaction. Generally, Rh–ODT NPs were inactive, Rh–PVA NPs exhibited distinct activities in solution (aqueous biphasic catalysis) and as a supported catalyst, and Rh–TOAB NPs exhibited similar activities in solution and after immobilization. This last result opens the opportunity for the preparation of highly active Rh NP catalysts both in solution and as a heterogeneous catalyst. Additionally, the stability of the nanoparticles depends on the choice of ligand and on the functionalization of the support surface before immobilization. By optimizing the catalyst synthesis and reaction conditions, turnover frequencies as high as 700,000 h−1 where observed for stable and recyclable catalyst.

International audience; The solution synthesis of rhodium nanoparticles (Rh NPs) was achieved from the organometallic complex [Rh(η3-C3H5)3] under mild reaction conditions in the presence of a polymer (PVP), a monophosphine (PPh3) and a diphosphine (dppb) as a stabilizer, leading to very small Rh NPs of 2.2, 1.3 and 1.7 nm mean size, with PVP, PPh3 and dppb, respectively. The surface properties of these nanoparticles were compared using a model catalysis reaction namely, hydrogenation of cyclohexene, first under colloidal conditions and then under supported conditions after their immobilization onto an amino functionalized silica-coated magnetite support. PVP-stabilized Rh NPs were the most active catalyst whatever the catalytic conditions as a result of a strong coordination of the phosphine ligands at the metal surface that blocks some surface atoms even after several recycles of the supported nanocatalysts and limit the reactivity of the metallic surface.

The negative environmental impacts of industrial activity have been felt day-to-day, encouraging global actions to reduce the waste generation of harmful and persistent pollutants. Microemulsion synthesis of silica-coated iron oxide magnetic nanoparticles offers a high potential for several applications; however the process generates hazardous wastes that are difficult to treat and dispose of. In this study, cyclohexane and methanol were separated using phase decantation, distillation, and temperature reduction. The recovered solvents were reused in the same synthesis more than 20 times and the recovered surfactant IGEPAL® CO-520 was reused twice, suggesting the method applied has potential for continuous recycling.

Quantification of metal loading in supported catalysts is imperative; however, the analytical methods are usually time-consuming, expensive, and require sophisticated equipment and sample extraction with hazardous and corrosive strong acids. Herein, we report a new method for quantification of metal in supported catalysts using slurry sampling flame atomic absorption spectrometry. The slurry sampling method was used for determination of gold and the results were similar to those obtained with the traditional extraction method using aqua regia; however, it overcomes the main drawbacks associated with sample digestion by avoiding the use of concentrated toxic reagents, minimizing sample manipulation, and consequently, reducing the risks of contamination and the sample preparation time. Ultrasound radiation optimization associated with the solvent, mass of sample, concentration, and matrix effect in the slurry analysis allowed direct analysis by using the calibration in aqueous medium. The slurry sampling procedure could be applied to other catalysts with different supports and in bimetallic systems.

Au nanoparticles (Au NPs) have gained significant attention as catalysts for the selective oxidation of alcohols; however, the catalytic activity is highly dependent on the presence of a base. Alternatives to the use of strong bases, such as NaOH, are still needed. Here, we explored the basicity of magnesium ferrite/oxide supports to study the catalytic behaviour of supported Au NPs for the oxidation of benzyl alcohol. The presence of Mg2+ ions in the ferrite structure improved the catalytic activity of supported Au NPs to ca. 35% conversion in the absence of an additional base. After modifying the support with MgO, the catalytic activity of supported Au NPs was further improved to ca. 50% conversion, but the catalyst deactivated in successive recycling tests. When the catalysts were tested in the presence of a sub-stoichiometric amount of K2CO3, they became more active and remained stable upon recycling with no loss of activity and selectivity for the preferential production of benzoic acid.

O objetivo deste Account e fornecer uma visao geral de nossas atividades atuais de pesquisa, as quais envolvem a sintese e modificacao de nanomateriais superparamagneticos para aplicacao na area de separacao magnetica e catalise. Primeiramente, uma introducao ao magnetismo e a separacao magnetica e feita. Em seguida, estrategias sinteticas que tem sido desenvolvidas para gerar nanoparticulas superparamagneticas revestidas esfericamente por silica e outros oxidos, com destaque a sistemas bem caracterizados e preparados por metodologias que geram amostras de elevada qualidade e que, a principio, podem ser produzidas em maior escala, sao discutidas. Uma serie de catalisadores magneticamente recuperaveis preparados em nosso grupo de pesquisa pela combinacao unica de suportes superparamagneticos e nanoparticulas metalicas e destacada. Este Account e concluido com observacoes pessoais e perspectivas neste campo de pesquisa. The aim of this Account is to provide an overview of our current research activities on the design and modification of superparamagnetic nanomaterials for application in the field of magnetic separation and catalysis. First, an introduction of magnetism and magnetic separation is done. Then, the synthetic strategies that have been developed for generating superparamagnetic nanoparticles spherically coated by silica and other oxides, with a focus on well characterized systems prepared by methods that generate samples of high quality and easy to scale-up, are discussed. A set of magnetically recoverable catalysts prepared in our research group by the unique combination of superparamagnetic supports and metal nanoparticles is highlighted. This Account is concluded with personal remarks and perspectives on this research field.

Despite all the advances in the application of nanoparticle (NP) catalysts, they have received little attention in relation to the hydroformylation reaction. Herein, we present the preparation of a hydroformylation catalyst through the immobilization of air-stable rhodium NPs onto a magnetic support functionalized with chelating phosphine ligands, which serves as an alternative to air-sensitive precursors. The catalyst was active in hydroformylation and could be used in successive reactions with negligible metal leaching. The interaction between the rhodium NPs and the diphenylphosphine ligand was evidenced by an enhancement in the Raman spectrum of the ligand. Changes occurred in the Raman spectrum of the catalyst recovered after the reaction, which suggests that the rhodium NPs are precursors of active molecular species that are formed in situ. The supported catalyst was active for successive reactions even after it was exposed to air during the recycling runs and was easily recovered through magnetic separation.