Synergistic Effect of Oxygen Vacancies and Ni Species on Tuning Selectivity of Ni/ZrO₂ Catalyst for Hydrogenation of Maleic Anhydride into Succinic Anhydride and γ-Butyrolacetone.

Lili Zhao,Min Zhao,Yin Zhang,Tiancun Xiao,Tianjie Wu,Wenjun Yan,Yongxiang Zhao,Haitao Li,Jianghong Zhao,Yongzhao Wang

doi:10.3390/nano9030406

Abstract

ZrO2 nanoparticles, ZrO2 (P) and ZrO2 (H), with different tetragonal phase contents, were prepared. ZrO2 (P) possessed higher tetragonal phase content than ZrO2 (H). Ni/ZrO2 catalysts (10% (w/w)), using ZrO2 (P) and ZrO2 (H) as supports, were prepared using an impregnation method, and were characterized using XRD, Raman, H2-TPR, XPS, and H2-TPD techniques. Their catalytic performance in maleic anhydride hydrogenation was tested. The Ni/ZrO2 (P) catalyst exhibited stronger metal-support interactions than the Ni/ZrO2 (H) catalyst because of its higher number of oxygen vacancies and the low-coordinated oxygen ions on its surface. Consequently, smaller Ni crystallites and a higher C=C hydrogenation activity for maleic anhydride to succinic anhydride were obtained over a Ni/ZrO2 (P) catalyst. However, the C=O hydrogenation activity of Ni/ZrO2 (P) catalyst was much lower than that of the Ni/ZrO2 (H) catalyst. A 43.5% yield of γ-butyrolacetone was obtained over the Ni/ZrO2 (H) catalyst at 210 °C and 5 MPa of H2 pressure, while the yield of γ-butyrolactone was only 2.8% over the Ni/ZrO2 (P) catalyst under the same reaction conditions. In situ FT-IR characterization demonstrated that the high C=O hydrogenation activity for the Ni/ZrO2 (H) catalyst could be attributed to the surface synergy between active metallic nickel species and relatively electron-deficient oxygen vacancies.

Highlights

Maleic anhydride (MA), as the third most important anhydride in commercial use, can be hydrogenated to produce succinic anhydride (SA), γ-butyrolacetone (GBL), 1,4-butanediol (BDO), and tetrahydrofuran (THF) products (Figure 1)
The results showed that the hydrogenation products were SA and GBL, with no THF and other products being detected
Generally, the catalytic performance of supported catalysts is intrinsically linked to the active metal sites and supports, including the active metal and metal-support interactions

Summary

Introduction

Maleic anhydride (MA), as the third most important anhydride in commercial use, can be hydrogenated to produce succinic anhydride (SA), γ-butyrolacetone (GBL), 1,4-butanediol (BDO), and tetrahydrofuran (THF) products (Figure 1). The process remains a challenge because of the coupled structure of the C=C and C=O bonds in MA molecules [3]. The coupled molecular structure leads to a delocalization of the electron density in the C=C and C=O bonds This makes it difficult for the selectively hydrogenation. This makes it difficult for othfethselCec=tiCveblyonhdydtoroogbetnaaintioSnAo, fotrhfeorCt=hCebCo=nCd atondobCta=iOn SbAo,nodrsftoor othbetaCin=CGaBnLd. ICn=aOdbdoitniodns,tMo oAbthaains aGdBiLff.eIrnenatdmdiotiloencu, lMarAsthruasctaurdeifffreormenot tmheorlelcinuelaarr sctornujcutugaretefdrommoloetchuelresli,nseuacrhcaosnjcurgoatotendalmdeohleycdueleosr, asucrcohleaisn,criontothnatldiethiys daecoormapcrooulenidn,winitthhaat fiitvies-ma ceommbpeoreudndcywcliitch satrfuivcetu-mree.mTbheeresdpceyccialilcgsetroumcteutriec.

ZrO2 Preparation

Structure Characterizations

Catalytic Activity Tests

Raman Spectra

Findings

Discussion