Changing others without changing yourself
Providing a 'space' for reactions
Chemical reactions need a 'space' where reactants can meet. A catalyst provides that space.
Catalysts don't change before or after reactions
Promotes encounters and changes for others
Reduces activation energy
Like a hotel lounge or a concierge who provides meeting opportunities. They don't change themselves, but they connect people and create new relationships.
Ea = 335 kJ/mol
Dissociation of N≡N triple bond (941 kJ/mol) is rate-limiting. Extremely high temperature and pressure required; impractical reaction rate.
Ea = 150 kJ/mol (Literature: 144-170 kJ/mol)
N₂ dissociates stepwise on Fe surface. At 400-500°C and 200 atm, produces 150 million tons of ammonia annually supporting global food production.
There are various 'types' of catalysts. The atmosphere of the space they provide differs by catalyst.
Refined, quiet, comfortable, clean
Exhaust gas (CO, NOx), hydrogen and oxygen
"In our lounge, we clean exhaust gas and generate electricity from hydrogen. We await you in a refined space."
Rugged, practical, large-scale, lively
Nitrogen (N₂), carbon monoxide (CO), coal
"Feeding the world from the factory cafeteria. Converting nitrogen from the air into fertilizer, supporting half of humanity."
Artisanal, precise, creative, chemical toolmaker
Organic halides (R-X), aldehydes, ketones
"Creating C-C bonds as 'skeletons' in the craftsman workshop. Supporting the foundation of organic chemistry from pharmaceuticals to fragrances."
Industrial, high-temperature, mass production, world's basic chemicals
Sulfur dioxide (SO₂), oxygen (O₂)
"The heart of chemical plants. Used in 95% of sulfuric acid production, supporting industries worldwide."
Precision control, stereoregularity, high-tech, plastic revolution
Ethylene, propylene, alkylaluminum
"A commander precisely assembling polymer molecules. Nobel Prize in Chemistry 1963, pioneer of the plastic revolution."
Key point:Platinum group excels at refined reactions with small groups. Iron excels at large-scale, powerful reactions. Magnesium excels at precise organic synthesis. Vanadium excels at industrial oxidation reactions. Zirconium excels at stereochemical control in polymer synthesis. Each has their specialty.
CO + ½O₂ → CO₂ (Pt, Pd触媒)
2NO → N₂ + O₂ (Rh触媒)
CₓHᵧ + O₂ → CO₂ + H₂O (Pt, Pd触媒)
Simultaneously purifies three pollutants (CO, NOx, HC). Cleans over 98% of automotive exhaust gas.
アノード: H₂ → 2H⁺ + 2e⁻ (Pt触媒)
カソード: O₂ + 4H⁺ + 4e⁻ → 2H₂O (Pt触媒)
Generates electricity from hydrogen and oxygen. The core of clean energy.
N₂ + 3H₂ ⇌ 2NH₃ (Fe₃O₄触媒, 400-500°C, 200-300気圧)
Converts atmospheric nitrogen (N₂) into ammonia (NH₃). A raw material for fertilizers, this technology supports half of the world's population.
Feeding the world from the 'factory cafeteria' — Nobel Prize in Chemistry (1918)
nCO + (2n+1)H₂ → CₙH₂ₙ₊₂ + nH₂O (Fe/Co触媒)
Synthesizes liquid fuels from coal and natural gas. Large-scale plants operate in Germany and South Africa.
R-X + Mg → R-Mg-X (無水エーテル中、Mg触媒)
R-Mg-X + R'-CHO → R-R'-CH-OMgX → R-R'-CH-OH (C-C結合形成)
Forms Grignard reagent (RMgX) from organic halides (R-X) and magnesium. A fundamental reaction for C-C bond formation in organic synthesis.
1912 Nobel Prize in Chemistry (Victor Grignard) — Revolutionized organic chemistry
Grignard reagents are indispensable in modern chemistry as a 'craftsman's tool' for assembling complex organic molecules.
SO₂ + ½O₂ → SO₃ (V₂O₅触媒, 400-500°C)
SO₃ + H₂O → H₂SO₄ (硫酸の生成)
Sulfuric acid is the most produced chemical in the world (over 200 million tons/year). Over 95% uses V₂O₅ catalyst. Foundation for fertilizers, batteries, steelmaking, and all industries.
'Heart of chemical plants' — A foundational catalyst supporting the world economy
C₄H₁₀ + 3.5O₂ → C₄H₂O₃ + 4H₂O (V₂O₅/MoO₃触媒)
Selectively oxidizes butane to synthesize maleic anhydride. Important raw material for resins, coatings, and pesticides.
n C₂H₄ → (C₂H₄)ₙ (TiCl₄/ZrCl₄ + Al(C₂H₅)₃)
Synthesis of stereoregular polymers (isotactic, syndiotactic)
Precisely polymerizes ethylene and propylene to synthesize polymers with stereoregularity. This enabled plastics with superior strength and transparency.
1963 Nobel Prize in Chemistry (Karl Ziegler, Giulio Natta) — The Plastic Revolution
Zirconium-based catalysts support modern plastic industry as a 'commander' precisely controlling polymer chain growth.
The Fe-N bond strength is just right (not too strong, not too weak). It's a 'comfortable place' for nitrogen. Platinum's nitrogen adsorption is too weak.
The adsorption-desorption balance of CO and O₂ is optimal. High activity even at low temperatures (300-500°C). Iron lacks low-temperature activity.
The Mg-C bond is moderately polarized with high nucleophilicity. It readily reacts with organic halides to form Grignard reagents. Ideal as a 'craftsman's tool' for C-C bond formation.
V₂O₅ can repeat 'redox cycles' of supplying and removing oxygen. It has high selectivity for oxidizing SO₂ to SO₃ and works efficiently at moderate temperatures of 400-500°C.
The coordination structure of the Zr atom precisely controls the insertion direction of monomers. It grows polymer chains with stereoregularity (isotactic), dramatically improving mechanical strength and transparency.
In the electrochemical world too, the 'ease of reaction' varies greatly by catalyst. This is shown by the overpotential (η).
E: Actual electrode potential
E₀: Equilibrium electrode potential (theoretical)
Large overpotential = reaction is difficult (need to work hard)
Small overpotential = reaction is smooth (can react relaxed)
a: Tafel constant (material dependent)
b: Tafel slope (reaction mechanism dependent)
i: Current density
This equation shows how overpotential changes depending on the electrode material.
Reaction: 2H⁺ + 2e⁻ → H₂ (hydrogen evolution)
| Electrode Material | Exchange Current Density i₀ (A/cm²) | η @ i = 10 mA/cm² (V) |
|---|---|---|
| Platinum (Pt) | 10⁻³ | -0.03 |
| Iron (Fe) | 10⁻⁶ | -0.48 |
Overpotential difference: ~0.37 V
This difference represents the 'comfort of the space.'
In platinum's space, hydrogen ions can react relaxed.
In iron's space, they need to work harder to react.
Volmer: H⁺ + e⁻ → Hₐd
Tafel: 2Hₐd → H₂ ↑
Adsorbed hydrogen (Hₐd) efficiently desorbs to form H₂ gas.
Volmer: H⁺ + e⁻ → Hₐd
Heyrovsky: Hₐd + H⁺ + e⁻ → H₂ ↑
The Heyrovsky reaction is slow, resulting in large overpotential.
The 'ease of reaction' varies completely by catalyst. This can be measured as overpotential. Platinum group has small overpotential and smooth reactions. Iron has large overpotential and requires more energy.
What kind of 'space' do you provide?
This is the same in life.
Provides a space for subordinates to grow. Doesn't change themselves but nurtures those around them.
Mediates conflicts in meetings and guides consensus. Doesn't express their own opinions but arranges the space.
Changes the workplace atmosphere and increases productivity. Works behind the scenes but has great impact.
Neither is superior.
What's important is providing a 'space' that leverages your characteristics.
Even without changing yourself, you can change the reactions around you. That is the power of a catalyst.