{
    "title": "Molybdenum-oxo catalyst hydrogen generator",
    "inventor_name": "Jeffrey Long, Christopher Chang, Hemamala Karunadasa",
    "publication_year": 2010,
    "device_name": "Moly-Oxo Hydrogen Generator",
    "goal": "Generate hydrogen gas from water cheaply and efficiently using an earth-abundant catalyst.",
    "problem_addressed": "High cost and limited availability of platinum catalysts for water-splitting; need for carbon-neutral, low-cost hydrogen production.",
    "concept_summary": "A molecular molybdenum-oxo complex (PY5Me2)Mo-oxo acts as a proton-reduction catalyst that operates in neutral, dirty, or seawater without organic additives, producing hydrogen with high turnover frequency under electrochemical or light-driven conditions.",
    "detailed_description": "The invention describes a high-valence molybdenum-oxo complex, [(PY5Me2)MoO]^2^+ (often paired with PF_6^- counter-ions), which dissolves in aqueous media and catalyzes the reduction of protons to H_2. In laboratory tests the catalyst achieved a turnover frequency of 2.4 mol H_2 * mol catalyst^-^1 * s^-^1 in neutral buffered water and demonstrated activity in seawater. The catalytic cycle involves sequential electron transfers at a negative electrode (~= 1.0-1.4 V vs SHE) followed by proton uptake, releasing H_2. The ligand scaffold can be modified to tune activity, and the system can be driven electrically or by light.",
    "category": "Chemistry & Chemical Processes",
    "principles": [
        "Catalysis",
        "Proton reduction",
        "Electrochemical water splitting"
    ],
    "scientific_domains": [
        "Chemistry",
        "Materials Science",
        "Renewable Energy"
    ],
    "mechanisms_of_action": [
        "Electron transfer to metal-oxo center",
        "Proton uptake and H_2 evolution"
    ],
    "materials": [
        "Molybdenum",
        "Pyridine (PY5Me2 ligand)",
        "Hexafluorophosphate (PF_6^-)",
        "Sodium phosphate",
        "Potassium chloride"
    ],
    "energy_sources": [
        "Electrical energy (electrolysis)",
        "Light (photocatalytic variant)"
    ],
    "inputs": [
        "Neutral or seawater",
        "Electrical voltage (~= 1.0-1.4 V vs SHE)"
    ],
    "outputs": [
        "Hydrogen gas",
        "Oxygen (by-product of water oxidation)"
    ],
    "claimed_performance": "Turnover frequency of 2.4 mol H_2 * mol catalyst^-^1 * s^-^1 in neutral buffered water; > 500 mol H_2 * mol catalyst^-^1 * s^-^1 reported for related persulfido complex.",
    "experimental_evidence": "Laboratory electrochemical measurements showed the cited turnover frequencies and sustained H_2 evolution for at least three days in seawater.",
    "replication_status": null,
    "keywords": [
        "hydrogen generation",
        "molybdenum-oxo catalyst",
        "water splitting",
        "electrochemical catalysis",
        "renewable energy"
    ],
    "related_technologies": [
        "Platinum catalyst",
        "Hydrogenase enzymes",
        "Conventional electrolysis"
    ],
    "controversy_level": "low",
    "confidence_score": 0.9,
    "practicability_score": 0.7,
    "fringe_score": 0.2,
    "evidence_strength": 0.8,
    "risk_score": 0.1,
    "trl_estimate": 6,
    "source_urls": [
        "http://www.sciencedaily.com/releases/2010/04/100430154902.htm",
        "https://doi.org/10.1038/nature08969"
    ],
    "organizations": [
        "Lawrence Berkeley National Laboratory",
        "University of California, Berkeley"
    ],
    "applications": [
        "Hydrogen fuel cells",
        "Renewable energy storage",
        "Chemical feedstock production"
    ],
    "limitations": [
        "Requires external electrical or light energy",
        "Long-term catalyst durability not fully demonstrated"
    ],
    "open_questions": [
        "Scalability to industrial-scale hydrogen production",
        "Performance and stability in real seawater over months",
        "Cost of large-scale synthesis of the ligand-metal complex"
    ],
    "red_flags": [
        "No independent replication reported in the article"
    ],
    "evidence_quotes": [
        "Our new proton reduction catalyst is based on a molybdenum-oxo metal complex that is about 70 times cheaper than platinum.",
        "This complex catalyzes the generation of hydrogen from neutral buffered water or even sea water with a turnover frequency of 2.4 moles of hydrogen per mole of catalyst per second.",
        "The catalyst has been used to generate hydrogen for at least 3 days, with a turnover frequency of 1.47 million mol H2/mol catalyst per hour."
    ]
}