Single atom copper anchored on the sulfated zirconia for catalytic synthesis of dimethoxymethane via methanol no-oxygen dehydrogenation

Abstract

Single atom catalysts have attracted great attentions due to their maximum atom utilization and unique coordination structure. Herein, we developed a facile method to synthesize monoatomic copper on sulfated zirconia. The oxygen atoms in sulfate ions as the anchoring sites bonded with copper atom to form the tetradentate structure of Cu-O4. Then this general approach was extended to numerous metal oxides, including TiO2 and Al2O3. As a proof-of-concept application, the catalyst prepared on ZrO2 exhibited excellent catalytic performance in synthesizing dimethoxymethane via methanol no-oxygen dehydrogenation to achieve dimethoxymethane yield of 2.84% and the highest dimethoxymethane selectivity of 95.16% among those have been reported. This catalyst with special structure of monoatomic copper greatly weakens adsorption of the intermediate formaldehyde and avoids the excessive dehydrogenation of formaldehyde to carbon monoxide on the copper sites. Therefore, the generated formaldehyde desorbs from the copper sites and participates in the subsequent aldolization with methanol timely.