Selective Electrocatalytic Hydrodimerization of Acetylene to 1,3-Butadiene Over Neighboring Cu Dual Sites
Graphical Abstract
Electrochemical acetylene hydrodimerization mechanisms are deciphered by correlating the nuclearity of Cu site in Cu-MOFs with catalytic performance. The neighboring Cu dual sites in trinuclear Cu3-MOF orchestrate three critical steps: acetylene adsorption, C–C coupling of *C2H2 and *C2H3 intermediates, and 1,3-butadiene desorption, which contribute to the superior electrocatalytic selectivity of 1,3-butadiene.
Abstract
Selective electrocatalytic hydrodimerization of acetylene to 1,3-butadiene is a promising alternative to the energy-intensive naphtha steam cracking route, but remains a grand challenge due to competitive acetylene semihydrogenation and oligomerization. Herein, we profoundly investigate the underpinning structure–performance correlations between diverse nuclear number of Cu sites and acetylene hydrodimerization over benchmark Cu-MOFs electrocatalysts. The operando electrochemical Raman and Fourier transform infrared spectroscopies and theoretical simulations together reveal that single Cu site and double Cu sites are favorable for acetylene semihydrogenation and hydrodimerization, respectively. The as-designed neighboring Cu dual sites in trinuclear Cu3-MOF enable the adsorption of acetylene, subsequent C–C coupling of *C2H2 and *C2H3 intermediates into 1,3-butadiene as well as the desorption of 1,3-butadiene. As a result, the trinuclear Cu3-MOF affords a 1,3-butadiene selectivity of 91% and a high 1,3-butadiene production rate of 64 mmol g−1 h−1, which is about 2-fold and 20-fold higher than Cu2-MOF and Cu1-MOF. This work not only provides profound insights into the electrocatalytic mechanism of acetylene hydrodimerization but also guides the rational design of high-activity electrocatalysts.
Conflict of Interests
The authors declare no conflict of interest.
Open Research
Data Availability Statement
The data that support the findings of this study are available from the corresponding author upon reasonable request.
