Abstract:

Converting CO₂ into fuels and high-value chemicals through catalytic hydrogenation is an effective strategy to control CO₂ emissions and achieve sustainable energy development. A series of iron-based catalysts modified with Na and S were synthesized using a precipitation method, and the effect of promoter content on catalytic properties and the performance of CO₂ hydrogenation to C₂₊ alcohols was investigated. The Na-S dual promoters can alter the active phase composition and the electronic properties of involved Fe sites, which in turn influence the activation ability towards reactants and CO intermediates, and ultimately affect the catalytic activity and product distribution. Moderate addition of Na and S helped balance the dissociated and non-dissociated CO activation on iron catalysts, which could promote the coupling of alkyl and *CO species and consequently enhance the production of C₂₊ alcohols. The NaS-Fe-3 catalyst achieved 12.8% selectivity for C₂₊ alcohols at a CO₂ conversion of 32%. Iron is generally regarded as an active component for CO dissociation and mainly contributes to hydrocarbon production. Selective synthesis of C₂₊ alcohols over monometallic iron catalysts was rarely reported. The Na-S co-modification to modulate catalytic properties and product distribution, provides new insights into catalyst design and reaction pathway optimization.

Key words: carbon dioxide, hydrogenation, alcohol, catalyst, optimal design

摘要：

利用CO₂加氢合成燃料或高值化学品是控制碳排放、实现能源可持续发展的有效途径。采用沉淀法制备了Na和S共修饰的铁基催化剂，并探究了助剂含量对催化性质及CO₂加氢合成C₂₊醇反应性能的影响。结果表明，Na-S双助剂可通过电子效应调变活性相的组成及其铁位点的电子性质，从而改变催化剂对反应气及CO中间体的活化能力，最终影响反应活性与产物分布。适量的Na和S改性有助于平衡铁基催化剂上CO解离与非解离吸附的能力，促进烷基物种与活性*CO的偶联，进而促进C₂₊醇的合成。NaS-Fe-3催化剂可在32%的CO₂转化率下实现12.8%的C₂₊醇选择性，改变了传统对于单铁催化剂难以有效催化C₂₊醇合成的认识。这种通过双助剂改性调控催化性质的策略，为催化剂设计与反应路径调控提供了新的思路。

关键词: 二氧化碳, 加氢, 醇, 催化剂, 优化设计