Understanding the geometric and electronic factors of PtNi bimetallic surfaces for efficient and selective catalytic hydrogenation of biomass-derived oxygenates

Mechanism of Catalytic Transfer Hydrogenation for Furfural Using Single Ni Atom Catalysts Anchored to Nitrogen-Doped Graphene Sheets

“…As shown in Table , many other zeolites have been reported to have similar reaction pathways and reaction mechanisms for the CHT of furfural to furfuryl alcohol, and the energy barriers vary in a wide range from 0.82 to 1.63 eV as a result of the different modification of the zeolites or MOFs. − Therefore, the energy barrier of 0.83 eV for the single-metal Ni-doped Ni–N 3 -Gr in this study is lower than those of the zeolites or MOFs mentioned above. The noble metal catalysts ,− were reported to have relatively higher activity than non-noble metal catalysts. , For example, the PtNi hollow nanoframe was calculated to have a barrier of only 0.52 eV, much smaller than 1.17 eV of the Cu(111) surface. Interestingly, Cu 2 O­(100) was calculated to have an excellent activity for the CTH of furfural to furfuryl with an energy barrier of only 0.64 eV.…”

“…The furfural ring tends to adsorb on the surface of Pt, Pd, and Ni due to the strong interaction between the π bond of the furan ring and these metals, such that not only the aldehyde group but also the CC group bonds to the surface. , Instead, low-cost non-noble metal catalysts were usually designed for transforming furfural into furfuryl alcohol because of their stronger affinity for the CO bond. , For example, density functional theory (DFT) calculations show that Cu-based catalysts have high selectivity to alcohol products due to the thermodynamically favorable η 1 -(O) adsorption mode, , where only the O atom from the aldehyde group bonds to the metal site. The nickel-based catalysts were considered as alternatives to noble metals because of their considerable activity. − For example, the Ni metal was designed to enhance the chemoselective hydrogenation of furfural due to its excellent performance in hydrogen dissociation; , however, the Ni species tend to aggregate. Recently, the Ni nanoparticles were stabilized on a nitrogen-rich carbon core–shell structure and the thus obtained catalyst was utilized for chemoselective hydrogenation of the furfural to furfuryl alcohol with a high selectivity of 98% and a high conversion of 99% …”

Selective Hydrogenation of the Carbonyls in Furfural and 5-Hydroxymethylfurfural Catalyzed by PtNi Alloy Supported on SBA-15 in Aqueous Solution Under Mild Conditions

“…Mild conditions could improve the selectivity to C O hydrogenation and suppress the other side reactions (Chen et al, 2016;Chen et al, 2018). For example, Wu et al (2021) reported that PtNi hollow nanoframes could catalyze the FF hydrogenation with 99% yield of FFA in isopropanol within 12 h at 373 K under 2 MPa H 2 . Xiao et al (2021) reported that Pt 1 Sn 0.3 @HMSNs could yield 97% FFA in isopropanol within 5 h at 373 K under 1 MPa H 2 .…”

“…On the other hand, the high electron density of the Pt in PtNi alloy is beneficial for the hydrogenation of FF/HMF due to the dissociation of H 2 which needs the donation of d-denotation of Pt to hydrogen. The σ electrons of H 2 could be accepted by metal Pt occupied d-orbitals, which donated d-electrons to the σ* antibonding orbital of H 2 , leading the H-H bond weakened and easily to be cleaved (Wu et al, 2021). Moreover, hydrogen spillover is a phenomenon that the activated hydrogen atoms on the surface of active metal can migrate to the support (Merte et al, 2012;Karim et al, 2017;Yang et al, 2020).…”

“…For example, Jiang et al reported that PtNi alloys enhanced the selective C=O hydrogenation of cinnamaldehyde in alcohol, and the hydrogenation of C=C double bond of the α,β-unsaturated aldehydes was suppressed ( Jiang et al, 2014 ). Wu et al (2021) reported that PtNi hollow nanoframes could catalyze the FF hydrogenation with 99% yield of FFA at 373 K in isopropanol solution. However, it is always hard to separate or recycle these expensive and nano-size PtNi catalysts.…”