Hydrogen production via the aqueous-phase reforming of methanol catalyzed by Ru(ii) complexes of PNNP ligands

Chen，Zhijian1,2; Xia，Yihao2; Ma，Chong2; Wang，Qian2; Qin，Lei2; Zhu，Xiaofei1; Zheng，Zhiping2,3

2022

10.1039/d2qi01719a

Inorganic Chemistry Frontiers   Impact Factor & Quartile

2052-1553

2052-1553

Hydrogen (H) production by the aqueous-phase reforming of liquid organic hydrogen carriers such as methanol, ethanol, and formic acid has attracted much interest recently as it offers a safe and convenient means of producing H on demand by mitigating the costs and safety challenges associated with the storage and transportation of H. Using efficient catalysts operative under easily achievable conditions is the key to the success of such reactions. Herein four Ru(ii) complexes with PNNP ligands, namely [Ru(PhPPhCH =N(1,2-cyclohexylene)N CHPhPPh)Cl] (1), [Ru(PhPPhCH NCHCHN CHPhPPh)Cl] (2), [Ru(PhPPhCHNHCHCHN CHPhPPh)Cl] (3), and [Ru(PhPPhCHNHCHCHNHCHPhPPh)Cl] (4) were synthesized and evaluated for catalyzing the aqueous-phase reforming of methanol (APRM). Comparative studies between better performing 2 (than 1) and its closely related analogs 3 and 4 revealed the profound influence of the ligands on their catalytic activities with the best-performing 2 producing a maximum TON of 12 639 after 8 days. Mechanistic studies using in situH NMR and high-resolution electrospray ionization mass spectrometry (HRESI-MS) suggested the presence of two key intermediates, formulated as [Ru(PhPPhCH N-CHCH-N-CHPhPPh)(H)] (I1) and [Ru(PhPPhCH-NH-CHCH-N-CHPhPPh)(H)] (I2) bearing respectively the half and fully reduced PNNP ligands. Comparative studies revealed that I1 is more active than I2. A mechanism involving the association and activation of the substrate (i.e. CHOH, HOCHOH, and HCOOH) mediated by the cooperative Ru-N set-up, followed by the stage-wise release of H, is proposed.

SCI

English

Corresponding

National Natural Science Foundation of China["21971106","22101117"] ; GuangDong Basic and Applied Basic Research Foundation[2020A1515110990] ; Stable Support Plan Program of Shenzhen Natural Science Fund[20200925161141006] ; Jilin Provincial Science Research Foundation of China[20200403154SF] ; Start-Up Fund from SUSTech["Y01216127","Y01216227"] ; Distinguished Expert Fund from Nanshan District of Shenzhen[K19219502] ; Guangdong Provincial Key Laboratory of Catalysis[2020B121201002] ; Shenzhen Nobel Prize Scientists Laboratory Project (Shenzhen Grubbs Institute)[C17783101]

Chemistry

Chemistry, Inorganic & Nuclear

WOS:000889105000001

ROYAL SOC CHEMISTRY

2-s2.0-85142720897

Scopus

1.School of Chemistry and Life Science,Changchun University of Technology,Changchun,Jilin,130012,China
2.Department of Chemistry,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China
3.Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Catalysis,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China

Chen，Zhijian,Xia，Yihao,Ma，Chong,et al. Hydrogen production via the aqueous-phase reforming of methanol catalyzed by Ru(ii) complexes of PNNP ligands[J]. Inorganic Chemistry Frontiers,2022.

Chen，Zhijian.,Xia，Yihao.,Ma，Chong.,Wang，Qian.,Qin，Lei.,...&Zheng，Zhiping.(2022).Hydrogen production via the aqueous-phase reforming of methanol catalyzed by Ru(ii) complexes of PNNP ligands.Inorganic Chemistry Frontiers.

Chen，Zhijian,et al."Hydrogen production via the aqueous-phase reforming of methanol catalyzed by Ru(ii) complexes of PNNP ligands".Inorganic Chemistry Frontiers (2022).