Related Experiment Video
Updated: Feb 28, 2026
06:32
A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions
Published on: August 17, 2016
20.4K
Multiscale Mechanistic Insights into Hydrogen Production from Microalgae via Molten Hydroxide-Mediated Thermochemical
Jun Li1, Ling Lei1, Dian Zhong1
1State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, P. R. China.
Environmental Science & Technology
|February 26, 2026
Summary
Thermochemical conversion of microalgae in molten hydroxides enhances sustainable hydrogen production by suppressing tar and activating new pathways. This study reveals the multiscale mechanisms behind these improvements for efficient biomass-to-hydrogen technologies.
Area of Science:
- Biomass thermochemical conversion
- Sustainable hydrogen production
- Catalysis and reaction engineering
Background:
- Molten hydroxides offer high hydrogen yield and low tar in microalgae conversion.
- The detailed reaction network and enhancement mechanisms are not fully understood.
- Understanding these mechanisms is crucial for optimizing biomass-to-hydrogen technologies.
Purpose of the Study:
- To elucidate the multiscale reaction mechanisms of microalgae thermochemical conversion in molten hydroxides.
- To identify the key pathways and factors contributing to enhanced hydrogen production and reduced tar formation.
- To establish a mechanistic framework for designing efficient low-carbon hydrogen production systems.
Main Methods:
- Multiscale analysis integrating macro-scale (TG-FTIR-MS), mesoscale (model compound experiments), and microscale (DFT calculations).
- Coupled thermogravimetric-Fourier transform infrared spectroscopy-mass spectrometry (TG-FTIR-MS) for macro-scale observation.
- Density functional theory (DFT) calculations for microscale mechanistic elucidation.
Main Results:
- Molten hydroxides lower biomass decomposition temperature and suppress tar formation.
- Three distinct hydrogen production pathways were identified: organic catalytic cracking, aromatic volatiles reforming, and char alkalization.
- Aromatics reforming involves nucleophilic addition and C-H bond heterolysis, with deprotonation as the rate-limiting step.
Conclusions:
- A comprehensive multiscale mechanistic framework for hydrogen production from microalgae in molten hydroxides has been established.
- The study highlights the roles of OH- nucleophilic addition and C-H bond heterolysis in aromatics ring cleavage.
- This research provides insights for the rational design of advanced biomass-to-hydrogen technologies.
Related Concept Videos
02:13Reduction of Alkenes: Catalytic Hydrogenation
14.5K
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
14.5K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.9K
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
3.9K
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
13.2K
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
13.2K
01:21Green Algae
972
Green algae, also referred to as chlorophytes, are different from red algae in having the chloroplasts containing chlorophylls a and b, which give them their distinct green hue. However, they lack phycobiliproteins, preventing them from developing the red or blue-green pigmentation seen in red algae. In terms of photosynthetic pigment composition, green algae closely resemble plants and share a close evolutionary relationship with them. Taxonomically Green algae belong to Phylum Chlorophyta in...
972
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
9.2K
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
9.2K
03:08Hydroboration-Oxidation of Alkenes
11.8K
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
11.8K