What is Pseudo Boehmite?
Pseudo boehmite (also written pseudoboehmite, chemical formula AlOOH·nH₂O) is a poorly crystallized form of aluminum oxyhydroxide with high water content and nano-scale crystallite size (3-10 nm). It is the most important precursor for active alumina catalysts and is widely used as a peptizable binder in catalyst shaping.
When calcined at 450-600°C, pseudo boehmite transforms into high-surface-area gamma-alumina (γ-Al₂O₃) — the most widely used catalyst support in petroleum refining and petrochemical industries. The small crystallite size of pseudo boehmite enables gamma-alumina with surface areas of 200-380 m²/g, much higher than can be achieved from crystalline boehmite or gibbsite.
Technical Specifications
Standard Grades
| Parameter | PB-Low | PB-Standard | PB-High | PB-Ultra |
|---|---|---|---|---|
| Al₂O₃ (%) | ≥70 | ≥72 | ≥75 | ≥78 |
| SiO₂ (%) | ≤0.05 | ≤0.03 | ≤0.02 | ≤0.01 |
| Fe₂O₃ (%) | ≤0.03 | ≤0.02 | ≤0.01 | ≤0.005 |
| Na₂O (%) | ≤0.10 | ≤0.05 | ≤0.02 | ≤0.01 |
| CaO (%) | ≤0.03 | ≤0.02 | ≤0.01 | ≤0.005 |
| Loss on Ignition (%) | 25-30 | 23-27 | 20-25 | 18-22 |
| D50 (μm) | 20-40 | 30-50 | 40-80 | 50-100 |
| Surface Area (m²/g) | 180-220 | 220-260 | 260-300 | 300-320 |
| Pore Volume (cm³/g) | 0.3-0.4 | 0.4-0.5 | 0.5-0.7 | 0.6-0.8 |
| Bulk Density (g/cm³) | 0.4-0.5 | 0.5-0.6 | 0.6-0.7 | 0.7-0.8 |
| Peptization Index | ≥95 | ≥97 | ≥98 | ≥98 |
Key Applications
- Catalyst Precursor: The dominant precursor for hydroprocessing catalysts (HDS, HDN, hydrocracking). Mixed with active metals (Mo, Ni, Co, Pt, Pd), shaped, dried, and calcined to produce finished catalyst extrudates, spheres, or pellets.
- Peptizable Binder: The standard binder for FCC catalyst manufacturing. Forms a stable alumina sol when peptized with acid (HNO₃ or HCl), binding the zeolite Y and matrix components into mechanically strong microspheres.
- Catalyst Washcoat: Coating binder for three-way catalytic converters (TWC), diesel oxidation catalysts (DOC), and SCR catalysts. Provides adhesion of washcoat to cordierite or metallic substrate.
- Active Alumina Production: Source of high-purity gamma-alumina for adsorbents, desiccants, and specialty catalyst carriers.
- Ceramic Fiber and Film: Precursor for high-purity alumina fiber used in refractory insulation, and for transparent alumina films used in electronics.
- Battery Separator Coating: High-purity pseudoboehmite used to coat lithium-ion battery separators, improving thermal stability and electrolyte wettability.
Why Choose Our Pseudo Boehmite?
- 4 standard grades + custom specifications to match your catalyst recipe
- Low Na₂O grades available (≤0.01%) — critical for catalysts where sodium poisons active sites
- High peptization index (≥97%) for smooth sol formation
- Customizable PSD and surface area — D50 from 5 to 100 μm, SA 180-320 m²/g
- ISO 9001:2015 certified with batch-to-batch CV <5% for key parameters
- 15+ years export experience — trusted by catalyst manufacturers in 30+ countries
- Free 1-2 kg sample for evaluation
Frequently Asked Questions
What is pseudo boehmite and how is it different from boehmite?
Pseudo boehmite (pseudoboehmite) is a poorly crystallized form of aluminum oxyhydroxide (AlOOH·nH2O) with high water content (n = 0.4-0.6) and very small crystallite size (3-10 nm). True boehmite has well-developed crystals with lower water content. Pseudo boehmite is the preferred precursor for active alumina because its small crystallite size and high surface area produce superior gamma-alumina catalysts after calcination. Pseudo boehmite is also the standard peptizable binder for FCC catalysts and other shaped catalyst carriers.
What is pseudo boehmite used for?
Main applications: (1) Catalyst precursor - converted to high-surface-area gamma-alumina for HDS, HDN, hydrocracking catalysts. (2) Peptizable binder for shaping FCC catalysts and other extrudates/spheres. (3) Coating binder for catalyst washcoats (TWC, DOC, SCR). (4) Active alumina manufacturing - pseudoboehmite + acid forms alumina sol used in ceramics, fibers, and thin films. (5) High-purity alumina precursor for sapphire, lithium battery separator coating, and specialty ceramics.
How is pseudo boehmite made?
Pseudo boehmite is manufactured by neutralizing aluminum salt solutions (typically aluminum sulfate or sodium aluminate) under controlled pH and temperature. The neutralization produces a gelatinous aluminum hydroxide precipitate which is then aged to develop the pseudo boehmite crystal structure, washed to remove sodium and sulfate ions, filtered, and spray-dried to fine powder. Quality control focuses on crystallinity, surface area, and impurity levels (especially Na, Fe, Si).
What is the difference between pseudo boehmite and aluminum hydroxide (ATH)?
Both are aluminum compounds but with different crystal structures and uses. Pseudo boehmite (AlOOH·nH2O) is a poorly crystalline precursor with high surface area (180-320 m²/g) used for catalyst manufacturing. Aluminum hydroxide (Al(OH)3) is a fully crystalline gibbsite with low surface area (<1 m²/g) used as flame retardant filler. They are NOT interchangeable: pseudo boehmite is reactive and converts to gamma-alumina on heating; ATH decomposes to alpha-alumina + water at 200-220°C.
What is the minimum order quantity for pseudo boehmite?
Standard grades: MOQ 500 kg. Custom PSD or surface area specifications: MOQ 1-2 metric tons. Free 1-2 kg samples available for evaluation (shipped within 5 days). Lead time: 7-15 days for standard grades, 25-40 days for custom specifications. We can produce from 0.5 MT to 200 MT per month. Packaging: 25 kg plastic-lined kraft paper bags, 500/1000 kg super sacks, or custom packaging on request.