Rhodium is a unique platinum group metal (PGM) which exhibits high corrosion resistance, low electrical resistance, produces extremely hard coatings, and is one of the most sought after catalyst materials due to its ability to function as a reductive catalyst. Rhodium oxides and base rhodium catalyst metals are used within a variety of catalytic processes and electronic components. It is estimated that over 80% of rhodium usage is in three-way catalytic convertors for catalysis of CO and NO gases from motor vehicle exhaust. Rhodium is commonly used in the Monsanto process for the production of methanol from acetic acid and is an important catalyst for other organic reactions such as chiral synthesis and the reduction of benzene to cyclohexane. Non-catalytic uses include optical coatings, neutron detectors to measure neutron flux levels in nuclear reactors, as electrical contact materials (due to its low electrical resistance), and as X-ray filters.
MemPro’s rhodium functionalized nanofibers consist of base aluminum oxide (Al2O3) nanofibers incorporated with nanoparticles of rhodium(III) oxide (or rhodium sesquioxide). Depending on operational requirements, functionalized nanofibers can be supplied with the rhodium(III) oxide as a hexagonal or orthorhombic crystalline structure depending on the thermal profile in which the fibers are produced. Our unique manufacturing process produces nanofibers with uniform dispersion of rhodium(III) oxide nanoparticles on the interior and exterior surfaces of Al2O3 fibers. Analysis of the rhodium nanoparticles reveals very consistent diameters (geometric size) within a range of 1 to 6 nm.
MemPro’s nanofibers are also available with platinum, rhodium, and palladium noble metals incorporated within a single nanofiber support material, manufactured to meet customer specifications.
Rhodium functionalized nanofiber materials are made to our customers’ specifications, according to their catalyst loading and base material requirements. Please contact us to order this product.
|Appearance||fibrous, non-woven, whitish-grey flake-like material|
|Structure||Al2O3 crystalline nanofiber material (gamma- or alpha- phase) with supported Rh/Rh2O3 nanoparticulates|
|Density||Al2O3 nanofibers: 4 gcm-3, rhodium nanoparticles: 8.2-12.41 gcm-3, bulk: 0.1 gcm-3|
|Surface area||Al2O3 nanofibers: 150 – 200 m2g-1, rhodium nanoparticles: m2g-1|
|Melting Point||Al2O3 nanofibers: 2072°C, rhodium nanoparticles: 1100°C Rh2O3 and 1964°C Rh|
|Thermal Conductivity||Al2O3 nanofibers: 30 Wm-1K-1, rhodium nanoparticles: 150 Wm-1K-1, bulk: NA|
|Electrical Conductivity||Al2O3 nanofibers: < 10-14 Sm-1, rhodium nanoparticles: 2.3×107 Sm-1, bulk: NA|
|Dielectric Strength||Al2O3 nanofibers: 1.4 MVm-1|
|Hardness||Al2O3 nanofibers: 9 (Mohs)|
|Fiber diameter||90 – 120 nm (ave.)|
|Fiber length||>5 µm|
|Refractive Index||Al2O3 nanofibers: 1.74926 (λ=1.36 µm)|
|Other||high chemical resistance, catalytically active, insoluble in water|
Rhodium(III) oxide (or rhodium sesquioxide) is used within a variety of products and process including catalysts systems, electronics, optical components, nuetron detection equipment, organic compound synthesis, and protective coatings. It is highly insoluble and posses relatively high thermal stability (which is sought-after property for glass), optical and ceramic applications. Interestingly, under CO oxidation conditions, rhodium oxides are much more efficient than rhodium metal. Also, rhodium and rhodium oxides are used extensively in motor vehicle catalytic convertors.
MemPro’s unique manufacturing process functionalizes ceramic nanofibers (Al2O3 or Cex Zr1-x O2) with uniform, well-dispersed rhodium(III) oxide nanoparticles on the exposed surfaces and within individual fiber matrices. Depending on the ceramic nanofiber base material, products can be tailored to meet specific customer needs. Although rhodium is useful in many applications, ceramic nanofibers functionalized with rhodium(III) oxide are typically used within catalytic applications. Some specific catalytic applications of ceramic nanofibers functionalized with rhodium(III) oxide include:
- motor vehicle exhaust treatment (catalytic convertors)
- production of hydrogen from ethanol (when used with cerium)
- ammonia oxidation
- methanation of CO2 (as rhodium base metal on Al2O3 nanofibers)
- oxidation of CO
For more information on rhodium-based catalyst products, please view the material data safety sheets and specification sheets in PDF format.
Spec sheet: ceramic nanofibers functionalized with rhodium catalysts
MSDS: Al2O3/Rh2O3 material data safety sheet