電化學(xué)將CO2還原為CH4是研究熱點,但也面臨挑戰(zhàn)。CH4是C1的還原產(chǎn)物,其形成涉及動力學(xué)緩慢的電子轉(zhuǎn)移過程,這導(dǎo)致其反應(yīng)選擇性差。2025年7月31日,中國石油大學(xué)戈磊,天津城建大學(xué)劉志鋒在國際知名期刊Advanced Functional Materials發(fā)表題為《Asymmetric Adsorption Site and Cu Vacancy Regulation in La–Cu Nanospheres to Promote CO2 Electroreduction Performance with Ultrahigh CH4 Selectivity》的研究論文,Zhixin Dai為論文第一作者,戈磊、劉志鋒為論文共同通訊作者。在本文中,作者報道了一種負載在碳上的含銅空位的LaCu納米球催化劑(La0.05Cuv1@C),其高效催化CO2轉(zhuǎn)化為CH4。實驗結(jié)果表明,La0.05Cuv1@C材料在-1.6 V下實現(xiàn)了73.3%的甲烷法拉第效率(FECH4),優(yōu)于對照樣本。原子級分散的La誘導(dǎo)電子轉(zhuǎn)移,形成不對稱吸附位點,增強CO2的吸附和活化;而銅空位優(yōu)化了中間體的吸附強度,抑制了C-C耦合,并促進了加氫途徑。La位點還可促進水解離,為后續(xù)的甲烷形成提供質(zhì)子。通過協(xié)同缺陷工程和雜原子摻雜,本研究為開發(fā)甲烷活化系統(tǒng)中的選擇性銅基催化劑建立了新范式。圖1:(a)La0.05Cuv1@C的合成路徑。(b)La0.05Cuv1@C、La0.05Cuv0@C、Cuv1@C和Cuv0@C的XRD圖譜。(c)La0.05Cuv1@C和 La0.05Cuv0@C的拉曼光譜。(d)La0.05Cuv1@C的HR-TEM圖像。(e)La0.05Cuv1@C的EDS元素分布圖。圖2:(a)La0.05Cuv1@C、La0.05Cuv0@C、Cuv1@C和Cuv0@C的Cu 2p XPS譜圖。(b)La0.05Cuv1@C和Cuv1@C的Cu AES譜圖。(c)La0.05Cuv2@C、La0.05Cuv1@C、La0.05Cuv0.5@C和La0.05Cuv0@C的EPR譜圖。(d)La L3的XANES譜圖。(e)La0.05Cuv1@C的La L3的FT-EXAFS譜圖。(f)La0.05Cuv1@C在La邊的WT-EXAFS圖。(g)Cu K邊XANES譜圖。(h)La0.05Cuv1@C的Cu K邊FT-EXAFS譜圖。(i)La2O3在La邊的WT-EXAFS圖。圖3:(a)La0.05Cuv1@C、La0.05Cuv0@C、Cuv1@C和Cuv0@C上甲烷的法拉第效率(FE)。 (b)La0.05Cuv1@C、La0.05Cuv0@C、Cuv1@C和Cuv0@C上甲烷的部分電流密度對比。 (c)16px; line-height: 1.75em;"},"namespaceURI":"http://www.w3.org/1999/xhtml"},"node",{"tagName":"span","attributes":{"mpa-font-style":"mdqtae111399","style":"font-size: 15px; font-family: mp-quote, -apple-system-font, BlinkMacSystemFont, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", Arial, sans-serif;"},"namespaceURI":"http://www.w3.org/1999/xhtml"},"node",{"tagName":"span","attributes":{"style":"color: rgba(0, 0, 0, 0.9); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: pre-wrap; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important;","data-pm-slice":"0 0 []","data-mpa-action-id":"mdqsrngk1ine"},"namespaceURI":"http://www.w3.org/1999/xhtml"},"node",{"tagName":"span","attributes":{"data-mpa-action-id":"mdqtwi06lpx","data-pm-slice":"0 0 []"},"namespaceURI":"http://www.w3.org/1999/xhtml"},"node",{"tagName":"span","attributes":{"data-mpa-action-id":"mds4w03j1j6o","data-pm-slice":"0 0 []"},"namespaceURI":"http://www.w3.org/1999/xhtml"},"node",{"tagName":"span","attributes":{"mpa-font-style":"mdqtae11c3u","style":"font-size: 15px; font-family: mp-quote, -apple-system-font, BlinkMacSystemFont, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", Arial, sans-serif;"},"namespaceURI":"http://www.w3.org/1999/xhtml"},"node",{"tagName":"span","attributes":{"data-mpa-action-id":"mds4taw7t49","data-pm-slice":"0 0 []"},"namespaceURI":"http://www.w3.org/1999/xhtml"}]">La0.05Cuv1@C、La0.05Cuv0@C、Cuv1@C和Cuv0@C的電容(Cdl)。 (d)La0.05Cuv0.5@C上產(chǎn)物的 FE。(e)La0.05Cuv0.5@C上產(chǎn)物的FE。(f)La0.05Cuv2@C上產(chǎn)物的FE。(g)La0.05Cuv1@C、La0.05Cuv0@C、Cuv1@C和Cuv0@C的奈奎斯特圖。 (h)各種電催化劑的甲烷電流密度和法拉第效率對比。 (i)La0.05Cuv1@C在-1.6 V下的穩(wěn)定性測試。圖4:(a)La0.05Cuv1@C的ATR-FTIRS譜圖。(b)La0.05Cuv1@C的反應(yīng)路徑圖。(c)Cuv1和LaCuv1上CO2還原為CH4的自由能圖。(d)H2自由能曲線圖。(e)Cuv1和LaCuv1的HER和CO2RR的超電勢(UL)及超電勢差(ΔUL)。(f)*CO二聚為*COCO在LaCuv1上的吉布斯自由能圖及CO脫附能。(g)*CO2在LaCuv1、LaCuv0和LaCuv2上加氫生成*COOH的吉布斯自由能圖。。圖5:DFT計算分析CO2在不同表面的吸附特性及其與活性位點的相互作用。(a)比較了CO2分子吸附在Cuv1和LaCuv1表面與自由CO2分子的部分態(tài)密度(PDOS),虛線表示費米能級。(b)展示了Cuv1和LaCuv1中Cu?C鍵的晶體軌道哈密頓能(COHP)曲線。COHP曲線揭示了Cu?C鍵的成鍵和反鍵軌道的能級分布。(c)描繪了CO2與Cu位點相互作用的結(jié)合模式。(d)和(e)分別展示了與*CO相關(guān)的d軌道的部分態(tài)密度(PDOS),其中紅虛線指示了d帶中心(?d)。(f)和(g)分別展示了Cuv1和LaCuv1上Cu 3dxy、3dyz、3dz2、3dxz和3dx2-y2的PDOS。(h)和(i)展示了*CO吸附的電荷密度差。黃色表示電子x積累,紅色表示電子耗盡。(j)展示了CO2的吸附構(gòu)型。(k)通過二維等值線圖展示了LaCuv1中CO2不對稱活化的電荷密度差分布。黃色表示電子積累,紅色表示電子耗盡。綜上,作者通過構(gòu)建具有銅空位的碳負載LaCu納米球催化劑(La0.05Cuv1@C),實現(xiàn)了高效的電化學(xué)CO2還原制甲烷。本文中,La0.05Cuv1@C催化劑在-1.6 V下實現(xiàn)了73.3%的甲烷法拉第效率,顯著優(yōu)于對照樣品。La的引入誘導(dǎo)電子轉(zhuǎn)移,形成不對稱吸附位點,增強CO2吸附和活化;銅空位則優(yōu)化中間體吸附強度,抑制C-C耦合,促進加氫路徑。此外,La位點還能促進水解離,為后續(xù)甲烷生成提供質(zhì)子。通過協(xié)同缺陷工程和雜原子摻雜,該研究為開發(fā)高選擇性銅基催化劑提供了新范式。該研究不僅提高了CO2電還原制甲烷的選擇性和效率,還深入揭示了La摻雜和銅空位在催化過程中的作用機制,為設(shè)計高性能銅基催化劑提供了理論依據(jù)。Asymmetric Adsorption Site and Cu Vacancy Regulation in La-Cu Nanospheres to Promote CO2 Electroreduction Performance with Ultrahigh CH4 Selectivity. Adv. Funct. Mater., 2025. https://doi.org/10.1002/adfm.202514227.