03937nas a2200205   4500008004100000022001400041245010400055210006900159260000800228300001600236490000700252520320800259100002103467700002203488700003303510700002503543700002503568700001603593856012203609       2026                        eng d  a0887-062400aAldol condensationof furfural to fuel precursor overCu-doped layered double hydroxide nanocatalysts0 aAldol condensationof furfural to fuel precursor overCudoped laye  cJUL  a15267-152870 v403 a<p>
	The conversion of biomass-derived molecules into high-value chemicals and biofuels represents a promising strategy to diminish dependence on nonrenewable fossil resources. Furfural, a lignocellulosic platform chemical, can undergo aldol condensation with acetone to yield valuable fuel precursor 4-(2-furyl)-3-buten-2-one (FAc). This work reports the nanotechnology-driven design and fabrication of active, recyclable, and structurally stable bifunctional Cu-doped layered double hydroxide (LDH) nanocatalysts (Cu = 1.73 wt %), developed via a memory-effect -assisted nanoscale reconstruction strategy. By integrating nanoscience-guided structural engineering with precise control over surface acidic-basic functionalities and material morphology, the resulting nanomaterials were exploited for the efficient conversion of furfural into FAc. The structure-activity relationships, recyclability, and catalytic robustness were assessed by characterizing the fresh and spent nanocatalysts using numerous techniques (XRD, N2 sorption, 27Al NMR, XPS, FE-SEM, EDX, TEM, ICP-OES, CO2-TPD, NH3-TPD, FT-IR, DLS, TGA, UV-Visible-DRS, and H2-TPR). These investigations provide fundamental nanoscience insight into how the rehydration process governs the physicochemical evolution of nanomaterials (acid-base, morphology, structure, and textural properties) and how these parameters collectively dictate the performance of reconstructed Cu-based nanocatalysts. A plausible mechanistic pathway for the cross-aldol condensation of furfural with acetone over the Cu-R24 nanocatalyst is proposed, wherein weak Br &amp; oslash;nsted basic sites, weak acidic sites, and surface oxygen defect species serve as the key catalytically active sites. Rehydrated Cu-R24 gives 100% furfural conversion with 84% FAc selectivity (50 degrees C, 2.5 h). Moreover, the nanocatalyst retained activity and stability for five recycles. The superior activity of Cu-R24 with a good TOF value (1.1 mmol &amp; centerdot;g-1 &amp; centerdot;min-1) arises from acid-base synergy, flower-shaped nanocrystals, Cu-induced electronic structure modulation and oxygen-defect sites evolution, a high BET surface area (205 m2 g-1), uniformly dispersed ultrasmall Cu2+ nanoparticles (1.8 nm), optimal densities of active weak Br &amp; oslash;nsted basic (0.62 mmol g-1) and weak acidic (0.26 mmol g-1) sites, and a mesoporous architecture (15.6 nm). XPS analysis revealed strong electronic coupling between Cu species and the Mg-Al host framework, along with the generation of surface oxygen defect sites, while CO2-TPD and NH3-TPD analyses confirmed well-balanced acidic-basic surface functionalities. Importantly, the combined XPS, CO2-TPD, and NH3-TPD results established that the synergistic modulation of electronic structure, oxygen defect density, and optimized acid-base characteristics played a decisive role in boosting the aldol condensation performance of the Cu-R24. By combining green, low-energy catalysis with biomass sustainability and nanoscale-engineered LDH memory-effect , this study delivers recyclable and stable Cu-based multifunctional nanocatalysts with industrial relevance for sustainable chemical manufacturing.</p>
1 aGode, Nilesh, G.1 aNagpure, Atul, S.1 aChilukuri, Satyanarayana, V.1 aBhagat, Shailesh, K.1 aRewatkar, Suresh, B.1 aSaini, Ajay  uhttps://library.ncl.res.in/content/aldol-condensationof-furfural-fuel-precursor-overcu-doped-layered-double-hydroxide