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Updated: Feb 1, 2026

Extraction of Ramie Fiber in Alkali Hydrogen Peroxide System Supported by Controlled-release Alkali Source

Extraction of Ramie Fiber in Alkali Hydrogen Peroxide System Supported by Controlled-release Alkali Source

Published on: February 6, 2018

強金属塩基相互作用による水素化触媒におけるアルカリ金属プロモーションの理解

Munam Jung¹, Maxim Park Dickieson¹, Pinzhang Chen¹

¹Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, Singapore.

Nature communications

|January 30, 2026

Abstract:

Alkali metals have been widely used as promoters in heterogeneous metal catalysts to improve activity, product selectivity, and stability. Despite their prevalence, the precise role remains not fully uncovered due to the complex interplay between catalytic components and reactants involving dynamic structural changes. Herein, we elucidate the promotional effect of alkali metal in hydrogenation reactions from a unified perspective. Using Na-doped Rh/TiO₂ as a representative system, we demonstrate a phenomenon, termed "Strong Metal-Base Interaction (SMBI)". The basic Na species (e.g. Na₂O) intimate to the Rh particles facilitates heterolytic H₂ splitting, capturing H⁺ while leaving H^- on Rh sites. Consequently, there are suppressed hydrogen spillovers from Rh to the TiO₂ surface and electron-rich Rh sites, fundamentally altering the catalytic behavior during hydrogenation. SMBI enables fine control of both activity and selectivity: Na doping shifts product selectivity in CO₂ hydrogenation completely from CH₄ to CO, enhances C=C hydrogenation via weakened H adsorption and electron-enriched Rh, and suppresses C=O and N=O hydrogenation due to restricted H spillover. These findings provide a unified framework for understanding alkali metal promotion and offer a rational approach for designing efficient hydrogenation catalysts.

キーワード:

水素化触媒アルカリ金属強金属塩基相互作用 CO2変換選択性制御

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Alkali Metals

Alkali Metals

Group 1 elements are soft and shiny metallic solids. They are malleable, ductile, and good conductors of heat and electricity. The melting points of the alkali metals are unusually low for metals and decrease going down the group, while the density increases going down the group with the exception of potassium (Table 1).
Table 1: Properties of the alkali metals

Metallic Solids

Metallic Solids

Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....

Catalysis

Catalysis

The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.

Bonding in Metals

Bonding in Metals

Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.

Metal-Ligand Bonds

Metal-Ligand Bonds

The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...

Strong Acid and Base Solutions

Strong Acid and Base Solutions

A strong acid is a compound that dissociates completely in an aqueous solution and produces a concentration of hydronium ions equal to the initial concentration of acid. For example, 0.20 M hydrobromic acid will dissociate completely in water and produces 0.20 M of hydronium ions and 0.20 M of bromide ions.