# US 9,433,938 B2 · Wet chemical and plasma methods of forming stable PTPD catalysts > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,433,938 B2 - Document ID: US9433938B2 - Status: Granted - Kind: B2 - Application number: 14/946,689 - Filed: 2015-11-19 - Published: 2016-05-26 - Granted: 2016-09-06 - Earliest claimed: 2011-02-23 - Assignees: SDCmaterials, Inc. - Applicants: SDCmaterials, Inc. - Inventors: Willibrordus G. M. Van Den Hoek; Maximilian A. Biberger - Web page: https://patentgrep.com/patent/US9433938B2 ## CPC - B01J 37/349: {making use of flames, plasmas or lasers} - B01J 23/42: Platinum - B01J 23/44: Palladium - B01J 35/393: {Metal or metal oxide crystallite size} - B01J 35/396: {Distribution of the active metal ingredient} - B01J 35/397: {Egg shell like} - B01J 35/45: Nanoparticles - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - B82Y 40/00: Manufacture or treatment of nanostructures - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES ## Abstract A nano-particle comprising: an interior region comprising a mixed-metal oxide; and an exterior surface comprising a pure metal. In some embodiments, the mixed-metal oxide comprises aluminum oxide and a metallic pinning agent, such as palladium, copper, molybdenum, or cobalt. In some embodiments, the pure metal at the exterior surface is the same as the metallic pinning agent in the mixed-metal oxide in the interior region. In some embodiments, a catalytic nano-particle is bonded to the pure metal at the exterior surface. In some embodiments, the interior region and the exterior surface are formed using a plasma gun. In some embodiments, the interior region and the exterior surface are formed using a wet chemistry process. In some embodiments, the catalytic nano-particle is bonded to the pure metal using a plasma gun. In some embodiments, the catalytic nano-particle is bonded to the pure metal using a wet chemistry process. ## Claims ### Claim 1 A method of forming nano-particles, the method comprising: forming a plurality of aluminum-palladium carrier nano-particles using a plasma gun, wherein the aluminum-palladium carrier nano-particles comprise an interior region and an exterior surface, the interior region comprising a mixed-metal oxide that includes aluminum oxide and palladium, and the exterior surface comprising pure metallic palladium; and affixing platinum nano-particles to the pure metallic palladium on the aluminum-palladium carrier nano-particles using a wet chemistry process; wherein forming the plurality of aluminum-palladium carrier nano-particles using the plasma gun comprises: loading a quantity of aluminum oxide material and a quantity of palladium material into the plasma gun in a desired ratio, wherein the aluminum oxide material and the palladium material are in powder form; vaporizing the quantity of aluminum oxide material and the quantity of palladium material using the plasma gun, thereby forming a vapor cloud comprising vaporized aluminum oxide and vaporized palladium; and quenching the vapor cloud, thereby condensing the vaporized aluminum oxide and the vaporized palladium into carrier nano-particles. ### Claim 2 (depends on 1) The method of claim 1, wherein the step of vaporizing the quantity of aluminum oxide material and the quantity of palladium material comprises: flowing a working gas into a reactor of the plasma gun; delivering energy to the working gas, thereby forming a plasma stream; and flowing the quantity of aluminum oxide material and the quantity of palladium material into the plasma stream. ### Claim 3 (depends on 2) The method of claim 2, wherein the working gas comprises argon and H2. ### Claim 4 (depends on 2) The method of claim 2, wherein the palladium in the interior region extends to and is bonded with the pure metallic palladium at the exterior surface. ### Claim 5 (depends on 1) The method of claim 1, wherein the palladium in the interior region extends to and is bonded with the pure metallic palladium at the exterior surface. ### Claim 6 (depends on 1) The method of claim 1, wherein the aluminum-palladium carrier nano-particles have an average grain size of 10 nanometers or less. ### Claim 7 (depends on 1) The method of claim 1, wherein the platinum nano-particles have a diameter of 1 nanometer or less. ### Claim 8 (depends on 1) The method of claim 1, wherein the platinum nano-particles have a diameter of approximately 0.5 nanometer. ### Claim 9 (depends on 1) The method of claim 1, wherein the mixed-metal oxide forms a center core of the aluminum-palladium carrier nano-particles. ### Claim 10 (depends on 9) The method of claim 9, wherein the mixed-metal oxide consists only of aluminum oxide and palladium. ### Claim 11 (depends on 1) The method of claim 1, wherein the wet chemistry process comprises: mixing a platinum solution with the aluminum-palladium carrier nano-particles; and bonding platinum nano-particles formed from the platinum solution to the pure metallic palladium on the aluminum-palladium carrier nano-particles. ### Claim 12 (depends on 11) The method of claim 11, wherein the platinum solution is a platinum nitrate solution or a platinum chloride solution. ### Claim 13 A method of forming a catalyst, the method comprising: providing a support structure; forming a plurality of aluminum-palladium nano-particles using a plasma gun; and bonding the plurality of nano-particles to the support structure; wherein forming the plurality of aluminum-palladium carrier nano-particles using the plasma gun comprises: loading a quantity of aluminum oxide material and a quantity of palladium material into the plasma gun in a desired ratio, wherein the aluminum oxide material and the palladium material are in powder form; vaporizing the quantity of aluminum oxide material and the quantity of palladium material using the plasma gun, thereby forming a vapor cloud comprising vaporized aluminum oxide and vaporized palladium; and quenching the vapor cloud, thereby condensing the vaporized aluminum oxide and the vaporized palladium into carrier nano-particles. ### Claim 14 (depends on 13) The method of claim 13, wherein: the support structure is a porous ceramic material; and the nano-particles are disposed within the pores of the ceramic material. ### Claim 15 (depends on 13) The method of claim 13, wherein the aluminum-palladium carrier nano-particles have an average grain size of 10 nanometers or less. ### Claim 16 (depends on 13) The method of claim 13, wherein the platinum nano-particles have a diameter of 1 nanometer or less. ### Claim 17 (depends on 13) The method of claim 13, wherein the platinum nano-particles have a diameter of approximately 0.5 nanometer.