Platinum Metals Rev., 2012, 56, (1), 55
Patents: January 2012
CATALYSIS – APPLIED AND PHYSICAL ASPECTS
Producing Iridium-Containing Catalysts
Exxonmobil Chemical Patents Inc, World Appl. 2011/096,996
A catalyst comprising of Ir dispersed on a support is prepared by: (a) treating a SiO2-containing support with one Ir compound and one organic compound (e.g. triethanolamine) to form a treated support consisting of an organic Ir complex on the support; (b) heating the treated support in an oxidising atmosphere at ~325–450ºC to form a partially decomposed organic Ir complex (this retains 10–95 wt% of the dry weight attributed to the complex before partial decomposition); and (c) heating the treated support in an reducing atmosphere at ~350–500ºC to convert the partially decomposed organic Ir complex into the Ir component. The partially decomposed organic Ir complex has one or more IR absorption bands between 2100–2200 cm–1 which were not present in the original organic complex.
Preparation of Tris(dibenzylidenacetone)dipalladium (chloroform)
Johnson Matthey Plc, World Appl. 2011/101,665
The catalyst Pd2(dba)3·CHCl3 is prepared in two steps: (a) a Pd(II) complex (selected from Pd(Hal)2, Pd(diolefin)(Hal)2 and Pd(CH3CN)(Hal)2) is reacted with an alkali metal halide (Li, Na or K halide) in an alcohol solvent at ~20–50ºC; (b) the product obtained from step (a) is reacted with a mixture comprising dba, CHCl3 and alkali metal acetate over 60 minutes at ~49–53ºC to form Pd2(dba)3·CHCl3. The molar ratio of Pd(II) complex:dba is preferably 2:3.20.
Ruthenium-Based Carbene Catalyst
Umicore AG Co KG, European Appl. 2,361,683; 2011
A method for preparing a Hoveyda-type Ru-based carbene catalyst with chelating alkylidene ligands by reacting a Ru alkylidene complex (for example, Ru indenylidene or Ru benzylidene) with an olefin derivate in a cross metathesis reaction in the presence of a polymer-supported cation exchange resin is claimed. The reaction temperature is 20–120ºC, preferably in the range of 20–100ºC and the reaction time is 0.5–4 h, preferably 0.5–2 h. After the reaction, the solvent(s) are removed, the remaining residues are suspended in a non-polar hydrocarbon solvent, and the precipitated catalyst is separated and dried.
CATALYSIS – REACTIONS
Thermo-Neutral Reforming of Hydrocarbon Fuel
Saudi Arabian Oil Co, US Patent 8,008,226; 2011
A multicomponent catalyst consisting of Ni, Ce2O3, La2O3, Pt, ZrO2, Rh and Re is used in a thermo-neutral reforming process to produce a H2-rich synthesis gas from a petroleum-based fuel. The fuel mixture, O2-rich gas and steam are introduced into an interior zone of a reactor which has a catalyst bed (combined combustion, steam and/or CO2 reforming catalyst). This mixture is preheated to ~380–450ºC and brought into contact with the catalyst bed at GHSV of ~30,000–70,000 h–1 which results in an exothermic reaction (the temperature is raised to ~800–900ºC) and causes an endothermic steam reforming reaction for a period of time sufficient to reform the liquid fuel to yield a H2-rich synthesis gas. The wt% of each constituent of the catalyst is: 0.5–15 Ni; 0.5–10 Ce2O3; 0.5–5 La2O3; 0.1–2 Pt; 0.5–3 ZrO2; 0.1–2 Rh; and 0.1–2 Re.
Platinum-Palladium in Exhaust System
Johnson Matthey Plc, US Appl. 2011/0,214,412
An exhaust gas aftertreatment system for a diesel vehicle consists of a NSC followed in a downstream direction by a CSF which has a wall flow filter containing inlet and outlet channels and comprises an oxidative catalyst with an OSC containing CeO2 or CeO2-ZrO2 and a Pd-rich mixture of Pt and Pd. The Pt:Pd weight ratio is < 1:10. The OSC of the oxidative catalyst is 20–50 wt%. A Pt-based oxidative catalyst is situated on the inlet channels and the Pd-rich Pt:Pd oxidative catalyst is located on the outlet channels.
Two Washcoat Layers on a Three-Way Catalyst
BASF Catalysts LLC, US Appl. 2011/0,217,216
A catalyst capable of effectively reducing CO in exhaust gas from an internal combustion engine consists of two washcoat layers: (a) a layer comprising of Pd impregnated on a CeO2-free OSC (for example, ZrO2-PrO2) and Pt impregnated on a refractory metal oxide (for example, Al2O3); (b) another layer comprising of Pt and Rh impregnated on a CeO2-containing OSC. The layers consist of 1–90 g ft–3 Pt; 1–90 g ft–3 Pd and 1–30 g ft–3 Rh.
Univ. Southampton, British Appl. 2,478,981; 2011
A catalyst with the composition PdxBiyMz is used in the anode of a fuel cell and optionally the cathode. M is a metal selected from Pt, Rh, Ir, Os, Ru, Re, Ni, Ag and Au or a combination; x = 0.1–0.7; y = 0.3–0.9; z < 0.1; and x + y + z = 1.
Hydrogen Production Apparatus
JX Nippon Oil Energy Corp, Japanese Appl. 2011-088,778
A H2 production apparatus includes a reforming section which carries out steam reforming of raw materials needed for H2 production. This part consists of a catalyst comprising of Pt, Pd and Rh on an Al2O3-containing support. The ratio of pgm on the support is 0.3–5:100 wt%. The Al2O3-containing support comprises of α-Al2O3 which has a pore volume of ≥ 50 nm and the diameter is 0.2–1.0 ml g–1, carrying 2–25 wt% of rare earth oxides and 0.1–15 wt% of alkaline earth oxides.
METALLURGY AND MATERIALS
Osmium in a Series of Penetrator Rods
J. Wisotzki, US Appl. 2011/0,189,325
A single crystal rod is made of an alloy of 40 wt% W, 40 wt% Ti and 20 wt% Os and is grown to the final usable shape in a support free float zoning process. The internal arrangement and control of the support free float zoning process consists of producing single crystal rods in a serial process; necking the intervals between each grown rod down to a diameter of 1.0 mm and separating the grown rods from each other. Compressed rods can be produced by obtaining a powder of high purity W, Ti and Os and compressing this with a die to reduce the O2 content between the granules of the powder. The single crystal penetrator rods do not break upon impact on a target and enable a size and weight reduction as no material is lost upon impact on the target.
APPARATUS AND TECHNIQUE
Surface-Enhanced Raman Scattering Substrate
Instytut Chemii Organicznej, European Appl. 2,369,327; 2011
A substrate for SERS consists of a semiconductor surface (GaN) containing whiskers which are coated with metal or alloy selected from Pt, Ag, Au or Cu. Each whisker contains a linear defect which may be a dislocation or an inversion domain and are connected with each other through terminals, forming conical bunches. The film thickness is 50–150 nm, length of the whiskers range from 0.2–2.0 µm, preferably 0.5–1.5 µm and the diameter ranges from 40–150 nm, preferably 50–70 nm.
MEDICAL AND DENTAL
Osmium(II) Arene Azo Anticancer Complexes
Univ. Warwick, World Appl. 2011/131,925
The Os-containing complexes, 1–3, can be used as cytotoxic agents, especially as anticancer or immunosuppression agents. Ar is an arene moiety; X is a halo or a donor ligand; Y represents a cyclic or bicyclic ring structure such as a 3, 4, 5, 6, 7 or 8 membered saturated or unsaturated heterocyclic ring; Z is N or CR′ (R′ = H, CN, N3, C1–C10 alkyl or aryl); R is a substituted or unsubstituted cyclic or heterocyclic ring; R1 is H, C1–C4 alkyl, OH, amino or substituted amino; Q is an ion which may be present or absent; and m and n are charges. In 3, Y is absent or is a C(R′)(R′′) group. These compounds can be prepared by reacting [ArOsX2]2 with an azo or imino containing ligand such as azopyridine or iminopyridine.
Palladium-Based Dental Alloy
DeguDent GmbH, US Appl. 2011/0,236,254
A Pd dominated dental alloy comprises of Au, Pd and Ag, one grain-growth inhibitor (Ru) and a grain-refinement control element (Ta, Nb or a mixture). The dental alloy contains (in wt%): 30–45 Au; 35–50 Pd; 10–25 Ag; 6–10 Sn; 0.03–1.0 Ru; and 0.03–2.0 grain-refinement control element.
Bridged Ring Metal Complexes
Sumitomo Chemical Co Ltd, British Appl. 2,478,450; 2011
An electroluminescent metal complex, 1, where X1 = C and X2 = C or N; M = Pt, Pd, Rh, Ir, Os or Ru; and A represents a group such as an amine or silyl group is claimed. Z1 and Z2 represent an optionally substituted aromatic hydrocarbon or heteroaromatic ring. The sum of squares of orbital coefficients of the outermost d orbital of M is ≥ 33.3%. The dihedral angle is 9–16º. The complex can be used in a light-emitting device or solar battery.
REFINING AND RECOVERY
Purification of Rhodium-Containing Solutions
Mitsubishi Mater. Corp, Japanese Appl. 2011-093,748
The purification of Rh-containing solution (which also contains NH4+ ions) involves adding NO2– to form a solution containing Rh nitrite complex. The purification process involves: (a) changing the pH to ≥ 1 by adding the NO2– salt and stirring the solution for ≥ 1 hour at 40ºC and pH ≤ 7 for gradually generating Rh nitrite complex ions and decomposing NH4+ ions; (b) heating the solutions to ≥ 70ºC and stirring for ≥ 1 h; and (c) solid-liquid separation to recover the precipitated free Rh nitrite complex ion solutions. (NH4)3Rh(NO2)6 may be generated by the addition of NH4+ salts to the recovered Rh nitrite complex ion solution. Rh recovery yield is improved using this process.